What Do Horse Flies Do? (Question)

Female horse flies feed on the blood of humans and other animals, while the males do not feed on blood. These pests can detect humans by movement, color, or carbon dioxide output. They do not feed indoors, but sometimes enter homes on accident through open windows and doors.

What are horse flies?

  • Horse-flies or horseflies (for other names, see common names) are true flies in the family Tabanidae in the insect order Diptera. They are often large and agile in flight, and the females bite animals, including humans, to obtain blood. They prefer to fly in sunlight, avoiding dark and shady areas, and are inactive at night.

What is the purpose of a horse fly?

Along with many other flying insects, horseflies are also a key food source for many other animals higher up the food chain. They help underpin other, more charismatic species such as bats and birds, while the aquatic larvae of the insects feed fish.

Do horseflies do anything good?

Horseflies are not good for anything. You can stretch your imagination and claim they are part of the ecosystem food chain. However, as a food source, its impact is negligible. Yes, birds eat horseflies, but not enough to make a meaningful impact on their diet.

What happens when a horse fly bites you?

After using small hooks to lock in, the horse fly sucks blood from the skin. Thus, the saliva injected while biting causes a sharp burning sensation. The saliva in the skin may also cause inflammation, itchiness, or bruise, around the site.

Do horse flies bite on purpose?

Yes, but only the females. Male horse flies do not bite because they do not feed on blood; they only feed on pollen and nectar. Female horse flies bite in order to feed on the blood of their victim; they require blood meals in order to be able to reproduce.

What do horse flies dislike?

Look for other ingredients in sprays — or make your own with natural oils — that are believed to be offensive to horse flies. These include peppermint, eucalyptus, lavender, clove, rosemary, basil, tea tree, lemongrass, catnip and cedar.

Do horse flies carry disease to humans?

Aside from the momentary pain they cause, horsefly bites are not generally harmful to humans. These bites are usually only a problem for horses. This is because horseflies carry equine infectious anemia, also known as swamp fever. When they bite an equine animal, they can transmit this life threatening disease.

Are horsefly bites painful?

A bite from a horsefly can be very painful and the bitten area of skin will usually be red and raised. You may also experience: a larger red, raised rash (called hives or urticaria)

Why do horsefly bites itch so much?

Unlike mosquitoes who release a mild anaesthetic, horseflies don’t, which is one of the reasons their bites are so painful. Once the horsefly has locked into your skin, it will suck the blood, causing a sharp burning sensation. In most cases, this will lead to itchiness, inflammation, and swelling around the bite area.

How long do horse flies last?

Horse flies pass through four distinct life stages: the egg, larvae, pupae, and adult fly. For most species, this sequence takes about one year to complete in full, though adult horse flies typically only live for 30-60 days.

Should you pop a horsefly bite?

Horsefly bite treatment Do not scratch the bite, even if it is itchy. Scratching it is likely to make the bite worse and increase the risk of bacterial infection developing. Do not use anything to clean the bite apart from soap and plain water. Home remedies such as bicarbonate of soda or diluted vinegar will not help.

What is the difference between a house fly and a horse fly?

A Horsefly is a group of similar flies considerably larger than a housefly. These flies can often reach 1-inch in length and are agile fliers. It’s found worldwide except in Hawaii, Greenland, Iceland, and the polar regions. Some species have noisy wings while others, including the common green horsefly, are silent.

Why do horse flies bite me and not others?

Only females bite because they need blood to produce eggs. They have jagged, saw-like teeth which slice open skin, then they release an anti-coagulant to stop the blood from clotting while they enjoy their meal.

Why am I finding horse flies in my house?

Horseflies enter homes through open doors and windows, especially when you’ve things in and around your house that attract them. Livestock is one of them. Detecting the scent of ammonia, the horse flies will get inside your home through the open doors, windows and through any gaps and cracks that they can find.

Do horseflies have teeth?

These insects don’t have teeth — not even the types of flies known to bite. Instead, they eat by partially liquifying it so they can siphon it with their mouthparts. The flies’ specialized feet receptors allow the creatures to begin enjoying a meal the instant they land.

Do horseflies eat mosquitoes?

Lice, Mites, Ticks and Mosquitoes It’s important to control these mites as they can infect humans.

What use are biting horseflies?

Anyone who has spent any amount of time in the woods in northern climates is familiar with the horsefly’s venomous bite. In comparison to their more delicate relative, the mosquito, which gently bites you and silently suckers your blood, they’re a lot more aggressive. The horsefly, on the other hand, has the ability to sneak up on you and attack. Their mouth parts do not puncture you pleasantly in the manner of a mosquito. “The horsefly’s mouth parts are shaped like a jig saw,” says the author.

According to Oddvar Hanssen, a senior engineer at the Norwegian Institute for Nature Research, “this is why we feel the bite quickly.” It then spits into the wound, preventing the blood from clotting, at least until a section of its mouth is used to sponge up our blood, at which point it dies.

Perhaps it makes more sense to be stealthy, as in the case of the mosquito.

A primitive species of fly

According to Hanssen, the horsefly and the mosquito are closely related, but they have evolved to occupy distinct positions on the evolutionary tree as a result of their divergent evolutionary histories. In order to live and breed, the horsefly has adapted his behavior to suit his own needs. One important consideration is that the female need a lot of blood in order to create eggs. In Norway, there are 32 different species of horsefly. There are around 4,000 species in the globe. (Photo courtesy of Eric Steinert / Wikimedia Commons – Creative Commons Attribution 3.0) Both mosquitoes and horseflies are members of the order Diptera, which is the scientific term for a vast group of flies that includes a variety of different species.

Only the female is capable of sucking blood.

Studying horseflies

In Norway, there aren’t many researchers that are interested in horseflies. When it comes to the horsefly, just one scholarly study from Norway can be found, according to ivind Gammelmo of the Biofokus Foundation. The page discusses the distribution of several varieties of horseflies in Norway and their characteristics. Norway is home to over 44,000 species of animals, birds, insects, plants, and other things that are known to science. There might be as many as 60,000 different creatures on the planet, according to scientific estimates.

“A lot of people believe that we have cataloged all of the species in Norway, but that is not the case,” says the researcher.

For example, we discover five to ten new species every year,” says Hanssen, who specializes in beetles and has discovered five to ten new species so far this year. Horseflies are known to exist in Norway in 32 different species, according to researchers.

Does not have great economic value

The horsefly performs a purpose in the ecosystem, however it is unclear what that function is at this time. (Photo courtesy of Magne Flten / Wikimedia Commons under a Creative Commons Attribution-ShareAlike 3.0 license.) Beyond just knowing how many different species of horseflies there are, why aren’t they being investigated further? It is not the horsefly species that is responsible for the most devastation. According to Gammelmo, “the reindeer warble fly and the cow warble fly, which are frequently mistaken for horseflies, can cause injury to animals.” The horsefly, on the other hand, is more of an inconvenience than a serious threat.

As a result, when the horsefly has been counted, identified as to where it lives, and categorised, the horsefly receives little more attention from scientists.

Something eats them

According to Hanssen, the horsefly has found a place in the ecology where it may thrive. He explained that it sucks blood for nourishment and to breed, and that it should be considered a part of the planet’s biodiversity, although an inconvenient one. And because horseflies are eaten by birds, the insects do serve a purpose, according to Gammelmo, despite the fact that it is not known how much of a bird’s diet is comprised of horseflies. As with all other insects and animals, they are a component of the environment.” Horseflies play an important role in the food chain and the ecology, just as other insects and animals do,” adds Dr.

– Visit forskning.no to read the Norwegian translation of this article.

Related content

|Download the PDF version of ENTFACT-511: Horse Flies and Deer Flies.

by Lee Townsend, Extension EntomologistUniversity of Kentucky College of Agriculture

Horse Fly and Deer Fly are two types of flies. Horse flies and deer flies are both bloodsucking insects that may be a major annoyance to cattle, horses, and people. Horse flies and deer flies are both considered to be a serious pest to humans. Horse flies are around 3/4 to 1-1/4 inches in length and have transparent or strongly colored wings, as well as brilliantly colored eyes, in most cases. Deer flies, which are smaller than horse flies and regularly bite humans, have dark bands across their wings and colored eyes that are similar to those of horse flies.

  1. The quantity of flies and the severity of their onslaught varies from one year to the next, depending on the season.
  2. It is possible that animals will harm themselves when fleeing from the insects.
  3. For their meal, Webb and Wells projected that horse flies would drink 1 cc of blood and that 20 to 30 flies dining for 6 hours would consume 20 tablespoons of blood, according to a USDA Bulletin 1218.
  4. Flies such as horse flies and deer flies are more active during the daytime hours.
  5. Once they have taken up residence on a host, they slit the skin with their knife-like mouthparts and feed on the blood pool that has formed.
  6. The soreness and swelling caused by bites normally subside within a few days.
  7. Bites may be painful, and general first aid-type skin lotions can assist to alleviate the discomfort.
  8. In terms of animal pests, male flies are of no significance because they feed on nectar.

The fly’s painful bites usually provoke a response from the victim, and the fly is compelled to move on to another host as a result. As a result, they may act as mechanical vectors for the transmission of some animal and human illnesses.


It is the muck around the borders of ponds and streams, as well as marshes and seepage sites, where horse fly and deer fly larvae grow and mature. Some are aquatic, while others grow in soil that is rather dry. Females lay batches of 25 to 1,000 eggs on vegetation that grows over water or in moist areas, depending on the species. They descend to the ground and feed on decaying organic debris as well as tiny creatures in the soil or water, which they acquire via this process. The larval stage, which can last anywhere from one to three years depending on the species, is the most common.


During the summer, deer flies are generally only active for brief periods of time at a time. Repellents such as Deet and Off (N-diethyl-metatoluamide) can give up to several hours of protection when used outside. Follow the directions on the label since some people might develop allergies after using a product for a long period of time. Also, check for age limitations. Permethrin-based repellents are intended for use on clothes alone, however they often give a longer duration of protection than other repellents.

Even after a remedy has been administered, these flies will continue to swarm and annoy you.

Hats with mesh face and neck veils, as well as neckerchiefs, may provide some protection under severe circumstances.


A set period of time throughout the summer is generally when the deer flies are most active. Resistants such as Deet and Off (N-diethyl-metatoluamide) can offer many hours of protection when used outdoors. Follow the directions on the label since some people might develop allergies after using a product for a long period of time. Also, check for age limits on the product label. Permethrin-based repellents are intended for use on clothes alone, however they often give a longer duration of protection than other types of repellents do.

Even after a medication has been administered, these flies will continue to swarm and swarm.

Hats with mesh face and neck veils, as well as neckerchiefs, may provide some protection in harsh situations.


It is extremely difficult to detect and/or destroy the breeding sites of horse flies and deer flies, and it is nearly impossible to do so. The fact that they spawn in environmentally sensitive wetlands raises concerns about the implications of drainage or pesticide treatment on non-target creatures or water supplies. Furthermore, these insects are excellent flyers and have the ability to move in from a distance. Breeding sites may be quite large or located a long distance distant from the location where the issues are occurring.

Some changes in behavior or the use of repellents may be necessary to allow for enjoyment of the outdoors.


Some goods may not be legal to use in your state or nation, depending on where you live.

As a reminder, ALWAYS READ AND COMPLY WITH LABELED INSTRUCTIONS FOR SAFE USE OF ANY PESTICIDE! Images courtesy of the University of Kentucky Entomology Department

Horse Fly

Common Name Horse Fly
Scientific Name Tabanus sp.(Diptera: Tabanidae)
Size 2/3 inches long
Colour Yellow-white to pinkish thick, tough skin
  • Unlike honey bees, adult flies are dark and hairy, strong, and approximately 2/3-inch long, visually resembling them except for the fact that they have only one pair of wings instead of two. The horse bot fly’s wings have slight smoky patches on them, similar to those of a bat. Fully-grown larvae (maggots) are up to 2/3 inch long and have thick, tough skin that ranges from yellow-white to pinkish in color. A pair of powerful, hook-like mouthparts are present on one end (the rear) and a blunt end (the front) on the other (the front). A ring of strongspines surrounds each segment of the body. Several additional species of bot flies are seen on horses, including the chin flyorthroat bot fly, Gasterophilus nasalis(Linnaeus), and the lipornose bot fly, Gasterophilus haemorrhoidalis(Linnaeus) and the lipornose bot fly, Gasterophilus haemorrhoidalis(Linnaeus). Horse flies are distinguished in part by the form of their eggs
  • They eat by sucking blood and may produce a painful and severe bite if they bite the victim. These flying pests are closely related to Deer flies in both appearance and behavior. Horse flies are similar in appearance to Deer flies, but are slightly bigger in size. A dark pattern can be seen on the wings of this fly, and its body can be either brown or black in color. The female of the species feeds on animal blood, while the male of the species is a pollen collector. Horse flies lay their eggs in marshy places near bays, lakes, ponds, and swamps, where they hatch into adult flies. These flies have larvae that feed on insects and may be seen growing in wetlands
  • The female of the species feeds on animal blood, while the male of the species is a pollen collector. Horse flies lay their eggs in marshy places near bays, lakes, ponds, and swamps, where they hatch into adult flies. Insect-eating larvae of this fly can be seen growing in wetlands where they feed on insects.
  • Unlike honey bees, adult flies are dark and hairy, strong, and approximately 2/3-inch long, visually resembling them except for the fact that they have only one set of wings. Slight smokey patches may be seen on the wings of the horse bot fly. Large larvae (maggots) can grow to be up to two-thirds of an inch in length and have thick, tough skin that is yellow-white to pinkish. A pair of powerful, hook-like mouthparts are found on one end (the rear) and a blunt end (the front) on the other (the front). There are strongspines around each segment of the body. In addition to the chin fly or throat bot fly (Gasterophilus nasalis(Linnaeus)) and the lipornose bot fly (Gasterophilus haemorrhoidalis(Linnaeus), several additional species of bot insects are seen on horses. Horse flies are distinguished in part by the form of their eggs
  • They feed by sucking blood and can produce a painful and severe bite if they bite the victim repeatedly. A close relative of Deer flies, these flying pests are a nuisance in the woods. Horse flies are a bit bigger in size than Deer flies, which is why they are frequently misunderstood. The female of this species feeds on animal blood, whereas the male of the species is a pollen collector. The wings of this fly feature dark patterns, and their body is brown or black in color. Horse flies lay their eggs in marshy places around bays, lakes, ponds, and swamps, as well as in the surrounding vegetation. These flies have larvae that feed on insects and may be seen growing in wetlands
  • The female of the species feeds on animal blood, while the male of the species is a pollinator. Horse flies lay their eggs in marshy places around bays, lakes, ponds, and swamps, as well as in the surrounding vegetation. Insect-eating larvae of this fly may be seen growing in wetlands where they feed on them.
  • This species’ larvae grow in the digestive systems of host animals throughout the winter months. Host excrement is contaminated with full-grown larvae that are discovered in the late winter and early spring months. Once they have reached this stage (instar), they burrow into the earth and construct a puparium out of the larval skin from their previous stage. It takes 3 to 10 weeks for them to develop into adult flies within the puparium
  • Adults are active from mid-summer until the end of the summer season. Female horses glue eggs to their coats, notably the coats of their front legs, but also the coats of their belly, shoulders, and rear legs, according to adult females. Depending on the appropriate stimulation (moisture, heat, and friction) provided by the horse licking or chewing egg-infested hair, eggs can hatch in 10 to 140 days. The larvae of the first stage (instar) enter the mouth and burrow into the tongue for around 28 days before molting and traveling to the stomach, where they remain for 9 to 10 months, growing into the third stage after approximately 5 weeks of development. Every year, there is a new generation.
  • In addition, they are major vectors of illnesses such as leucocytozoa and turkey sickness.
  • Adult horse fly and deer fly larvae are very ferocious biters. They cause animals to lose weight and have the potential to spread illnesses such as anaplasmosis, anthrax, and others.
  • Because of the nature of this fly, it is hard to completely remove it by spraying operations. The Advantage Fly Trap is the only trap that has had any success with biting flies (such as the Horse fly and the Stable fly). However, the success has been limited in the past. In certain circumstances, the revolutionary technology of this product allows us to attract and trap blood-sucking flies for the first time, which is a first in the industry. Yet, the results vary depending on the species and location
  • However, this trap may capture a wide variety of flies. If Horse Flies are discovered within a building, make sure that all probable access routes have been removed. They will not be discovered reproducing indoors in the same way that a house fly would be. The most effective method of controlling flies is to eliminate all available breeding grounds and food sources. As evidenced by the horse fly’s biology, this form of fly control is nearly impossible with this particular species.

How to Identify a Horsefly Bite and What to Do Next

There’s a good chance you’ve been bitten by a horsefly more than once in your life. If you’re not familiar with this venomous bug, it’s a huge, black fly that may be rather annoying. Generally speaking, you can tell it apart by its size. In comparison to the typical fly, a horsefly may grow to be as long as 1 inch (2.54 cm), making it significantly bigger than the usual fly. Continue reading to learn what you should do if you get bitten by a horsefly. If you’ve ever been bitten by a horsefly, you understand how painful it can be.

The mandible is the insect’s jaw in its most basic form.

The horsefly’s mandible is additionally equipped with tiny hooks that aid in the horsefly’s ability to latch in and feed more effectively.

This bite has the potential to cause:

  • The biting location may be bruised in certain circumstances, and there may be an itching and inflammation surrounding the bite region.

Aside from the temporary discomfort they cause, horsefly bites are not considered to be hazardous to people in general. Horses are generally the only ones who suffer from these bites. This is due to the fact that horseflies are known to transmit equine infectious anemia, often known as swamp fever. When they bite an equestrian animal, they have the potential to spread this potentially fatal illness. If a horse becomes infected with the virus, it may endure fever, hemorrhaging, and overall sickness.

  • Horseflies may be found all across North America, including Alaska.
  • Some localities, particularly during the summer months, are plagued with horseflies, which are virtually inescapable in some areas.
  • They prey on big creatures such as people, dogs, and, of course, horses, among other things.
  • They’re also drawn to carbon dioxide, which makes sense.
  • If you’ve ever had the impression that a horsefly was out for vengeance, you could be correct.
  • If their first bite does not provide them with the gratifying feast they were looking for, they have been known to pursue after their prey for a brief period of time.
  • The upper half of a horsefly is white, and it is usually distinguished by a few vertical black lines running vertically across it.

Using over-the-counter antiseptic spray or ointment, wipe the bite site and apply it to help keep the wound clean while also decreasing inflammation and itching The majority of the time, a horsefly bite will heal on its own within a few days.

Consult your doctor if you have any unexpected symptoms.

If you are having trouble breathing, have a rash that is spreading, or are experiencing increased discomfort, get medical treatment.

In the majority of cases, you will not suffer any negative side effects.

They will be able to analyze your bite and identify any necessary future actions.

Apply insect repellent before stepping outside to avoid being bitten by horseflies in the future. Wearing light-colored clothes is preferable if at all feasible. Horseflies are drawn to darker hues, therefore using a darker color may help keep them away from your home.

Horse Flies: Control, Bites, & Extermination of Flies

Adult horse flies are fast, powerful flyers, capable of flying for more than 30 miles and dispersing widely, yet they are not widely dispersed. They are most frequently attracted to moving and dark items. When horses fly, they tend to congregate on routes and roads, particularly in forested areas, where they await possible hosts. Horse flies are drawn to light and will swarm around windows from time to time.


Horse flies are generally found in or near woodlands or forests. Species are best visible when they are feeding in broad daylight, which is most often on windless, hot, bright days. On general, larvae grow in moist soil near sources of water, but this might vary.


The nectar of adult horse flies is their primary source of nutrition, but females require a blood meal in order to breed properly. Bites from female horse flies, especially those from large specimens, may be quite painful since their mouthparts are employed for ripping and lapping, as opposed to bites from mosquitoes, which just pierce the skin and sucking blood. In addition, female horse flies are quite persistent, and they will often continue biting a host until they are successful in obtaining their blood meal or are killed.

Some species are disease organism carriers, however in the United States, the majority of horse fly-vectored illnesses affect only cattle, not humans.

Truth About Horse Flies In Florida

Horse flies reach a length of between 12 and 14 inches when they are fully grown. Their strong bodies range in hue from gray to black, and their wings may be clear or somewhat foggy in appearance. Horse flies are distinguished by their huge, vivid green or purple eyes and their extremely small antennae. FEMALES are equipped with specialized blade-like mouthparts that they use to cut through the skin of a human or an animal, and they are also outfitted with spongy mouthparts that they use to suck in blood.

Do horse flies bite?

Yes, but only the girls are allowed to participate. Male horse flies do not bite because they do not feed on blood; instead, they feed on pollen and nectar, which are found in flowering plants. In order to reproduce, female horse flies bite in order to feed on the blood of their prey. They require blood meals in order to breed successfully. Horse flies can detect the presence of a human or animal by movement, warmth, or the carbon dioxide they release. It is common for them to bite the legs, limbs, or sometimes the entire torso of their victim.

Are horse flies dangerous?

Horse flies are regarded to be hazardous to both humans and animals, and this is supported by scientific evidence. In addition to being aggressive, horse fly bites are extremely painful because their mouthparts rip at the skin of their victim rather than merely piercing it like other flies do. Certain people may be allergic to their bites, and in some circumstances, a secondary infection may develop at the location of the bite, which is dangerous.

The good news is that they have not been linked to the transmission of illnesses to humans. The horse fly is responsible for the transmission of equine infectious anemia to horses and ponies, which has the potential to be lethal.

Where are horse flies found?

Horse flies are most commonly found in regions where there are huge populations of animals, and they may be found in both suburban and rural settings in enormous numbers. Horse flies love open environments that are close to water, such as fields and pastures. Females lay their eggs in the soil near bodies of water, while males do the same. It is common for horse flies to congregate along the borders of forested trails or along the sides of roadways, waiting for a host to pass by that they may bite and feed on.

Cold, windy days significantly lower their degree of activity.

How do I get rid of horse flies?

If you are having issues with horse flies on your property, call Keller’s Pest Control for assistance. They would be happy to help. Horse flies are a serious threat to humans and animals, and we have the knowledge, experience, and efficient pest management solutions to protect them. Give us a call at Keller’s Pest Control now to learn more about our fly control services.

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You may get help if you are having difficulties with horse flies on your property by contacting Keller’s Pest Control. People and animals are protected against horse flies by using our abilities, knowledge, and cost-effective pest management solutions. Give Keller’s Pest Control a call now to learn more about our fly control options.

Recent Blog Articles

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Horsefly bites: Identification and treatment

Please see below for links to our blogs and resources.

  • Take a look at the blogs and resources listed below:

Both vinegar and baking soda are unlikely to be of assistance. When a horsefly bites a person, no mouthpart or stinger will be left behind by the insect.

When to call a doctor

Unless an infection develops in the wound, the individual will not require medical treatment. A medical emergency should be called in the uncommon occurrence of a severe allergy that occurs shortly after a bite. When compared to other bug bites, horsefly bites are exceptionally painful and take a long time to recover. As a result of the technique through which the flies bite, they produce irritation. Horsefly bites are characterized by the following symptoms:

  • A cut, rather than a little puncture hole, has been made. When the horsefly bites, its mouthparts cut a wound in the skin in a scissor-like motion. After cutting through the skin, the fly “mops up” the blood with its mouthparts. The fly uses little hooks along its mouthparts to fix itself to the skin while it is sucking blood from the victim
  • This is how it survives.

The bite in the skin itself is generally red and surrounded by a raised region of skin, known as a weal or hive, which is a sign of an infection. Horsefly bites can be distinguished by their discomfort, redness, and swelling. People should be on the lookout for signs of spreading redness of the skin, as well as the appearance of pus or other discharge emanating from the wound site. Pain and swelling that worsen over time might potentially be signs of an infection. If a bite becomes infected, it normally does not happen right away, but rather takes at least a day or two to develop.

With the exception of swampfever, which may be lethal in horses, they do not transmit any diseases.

Symptoms of serious horsefly reactions

Although a severe allergy to horsefly bites is uncommon, it might manifest itself in the form of other symptoms such as:

  • Dizziness
  • Wheezing
  • Momentarily enlarged skin, particularly around the eyes and lips
  • And other symptoms.

Diarrhea; coughing; briefly enlarged skin, particularly around the eyes and mouth; dizziness

  • Diarrhea
  • Coughing
  • Briefly enlarged skin, especially around the eyes and mouth
  • Dizziness

People who have a severe allergy to horseflies have almost always been bitten by a horsefly at some point in their lives. The immune system then adjusts to protect the individual from future bites, but the individual becomes oversensitive to future bites as a result of the adaptation. People with severe allergies may need to carry an emergency epinephrine injection with them at all times in case they experience a biting response in the future. A horsefly is a flying insect that is most commonly seen in rural and farming environments, where it preys on big animals such as cattle.

  1. Additionally, they may be found in metropolitan areas near breeding places with plenty of water, such as a lake.
  2. Horseflies are need to bite large animals, such as horses, cattle, dogs, and people, as part of their life cycle in order to reproduce.
  3. Females must consume blood in order to maintain egg production.
  4. They are capable of sucking in around 200 milligrams (mg) of blood in a matter of minutes.
  5. The horsefly has been specifically bred to drink as much blood as possible in order to survive.
  6. Historically, horseflies have been employed in traditional Chinese medicine for their anti-clotting properties.
  7. When hot weather is accompanied by thunder, they can become much more of a nuisance.

What do horseflies look like?

In most cases, people who have a severe allergy to horseflies have also had their skin bitten by one at some point in their lives. The immune system adjusts in order to protect the individual against future bites, but the individual becomes oversensitive to future bites as a result of the adaptation process. In order to manage future bite responses, those who have severe allergies may need to carry an emergency epinephrine injection with them. A horsefly is a flying insect that is most commonly seen in rural and farming environments, where it preys on big animals, such as cattle.

  • Also seen in urban areas near nesting places with plenty of water, such as a lake, are brown-headed nuthatches.
  • Men do not bite because they do not have the proper mouthparts for horseflies, which are females only.
  • For reproduction, female horseflies require up to 0.5 milliliters (ml) of blood, which is a significant quantity given their small size.
  • Other blood-sucking arthropods like ticks and mosquitos go through a procedure that is somewhat similar to this.
  • It causes the release of chemicals that prevent blood clotting at the site of the skin puncture (see illustration).

For example, during the afternoon in the midst of summer, when it is hot and bright with little breeze, horseflies are more abundant than other insects. When thunder and hot weather combine, they may become even more of a nuisance.

  • They are substantial in size. Their colour is dark, and they have striped chests and black bellies to distinguish them from other animals. Their eyes are huge and complex in shape.

Horseflies are tough to avoid during the summer months due to the large number of habitats they have. There are certain practical precautions that a person may take, however, to lessen the likelihood of being bitten by a horsefly:

  • Shoes, long trousers, and long-sleeved blouses of a light hue should be worn to keep skin protected. Avoid going across tall grass. Use caution while using fragrant cosmetic items since they may attract insects. Keeping away from bodies of water during the summer months, where horseflies breed
  • Horsefly bites are unlikely to be prevented by using insect repellent, while it may be beneficial against mosquitoes, which may be present in the same places as the horseflies. Diethyltoluamide (DEET) is found in high concentrations in the most efficient repellents.

What Happens When a Horse Fly Bites You?

Light-colored shoes and long-sleeved clothes with a light color can keep your skin protected. It is best not to stroll over tall grass. Stay away from scented cosmetics since they may attract insects. It is best to avoid water during the summer months since horseflies breed there. Horsefly bites are unlikely to be prevented by the use of insect repellent, while it may be beneficial against mosquitoes that may be present in the same places as the horseflies. A 50 percent concentration of diethyltoluamide (DEET) is required for efficient repellents.

  • The horsefly has a scissor-shaped mouth to shred the skin
  • Little hooks to aid in the horsefly’s ability to latch in and suck more effectively.

Horseflies, on the other hand, shred the flesh of their victims, as opposed to mosquitoes, which pierce and suck blood from their victims’ skin. When the horse fly has been locked in with little hooks, it begins sucking blood from the skin. As a result of the saliva injected when biting, a severe burning sensation is experienced. Additionally, the saliva in the skin may create irritation, itching, or bruises surrounding the location of the injury. In certain rare instances, a horsefly bite might result in an allergic response, which includes the following symptoms:

  • Symptoms include: abdominal discomfort or vomiting, chest pain, difficulty swallowing, difficulty breathing, swelling of the face or mouth, feeling faint or lightheaded, rash, or flushing of the skin.

What is a horsefly?

Horseflies have a similar appearance to giant house flies. As the name implies, it is most usually associated with assaults on horses, cows, and other types of animals. They have the ability to spread life-threatening infections in horses, resulting in substantial economic loss. They have even been known to assault humans and pets.

How to treat horsefly bite?

Unlike house flies, horseflies are big and swarm in groups. As the name implies, it is most usually associated with assaults on horses, cows, and other types of farm animals. They have the ability to transmit life-threatening infections in horses, resulting in significant financial loss. Animals and people may be attacked by them.

  • Make the place as clean as possible. Make use of an antiseptic spray or ointment available over the market to assist clean the area and reduce inflammation and discomfort
  • If required, use an antihistamine to alleviate itching.

Make the place as clean as you possibly can. Make use of an antiseptic spray or ointment available over the market to assist clean the area and reduce redness and itching. If required, use an antihistamine to alleviate itching;

  • Swelling, excessive pus, foul odor, and any other peculiar symptoms are all signs of an infection.

Swelling, excessive pus, foul odor, and any other peculiar symptoms are all signs of infection.

  • Swelling, excessive pus, foul odor, and any other odd symptoms should be reported.

How can I prevent horse fly bites?

Increasing redness; swelling; excessive pus; foul odor; any other peculiar symptoms;

  • Stay away from areas where flies are most busy. Wearing light-colored, long-sleeved shirts, slacks, and caps will help to keep exposed skin covered. Take into consideration the use of a horsefly repellent that is effective against horsefly bites. Follow the instructions in the handbook to the letter. Install screens on your windows and doors. Remove any accumulated garbage, decomposing hay, straw, or other vegetation that may be attracting flies
  • And


What proportion of the human body is made up of water? Answer may be found here. 3/19/2021 – Medically reviewed by Dr. References The National Pest Management Association is an organization that promotes pest management. Horse Flies are a kind of fly that flies on horses. Medline Plus is a database of medical information. Bites and stings from insects. Department of Health and Human Services of the State of Washington Biting Flies are a type of fly that bites.


Some of the links in this post may be affiliate links to third-party companies such as Chewy, Amazon, and others. When you purchase something through one of these links, you are helping us to advance our aim to educate people about the world’s species. Occasionally, when a mosquito bites a person, they are unaware of the bite until the itching begins. The horsefly’s bite, on the other hand, is not subtle at all. Because her mouthparts are similar in design to a Swiss Army knife, she seems to employ all of them at the same time when obtaining the blood meal she requires.

Despite the fact that the horsefly, like the mosquito, is one of those insect pests that is ready for eradication, the eradication of such a widespread and persistent species does not appear to be realistic at this time.

5 Incredible Horsefly Facts!

  • The horsefly’s bite is not only unpleasant, but it also has the potential to transmit illnesses such as anthrax. If a horsefly larva lives in water, it has a siphon at the end of its body that allows it to breathe air
  • Otherwise, it does not. The horsefly larva, on the other hand, bites quite strongly. Horseflies only bite during the day, and especially on calm and sunny days
  • They are not active at night. It is the horsefly that is the world’s fastest flying insect, with the fastest recorded horsefly traveling at 90 miles per hour.

Horsefly Scientific name

Horseflies are members of theTabanusgenus, which has more than 1300 species and hundreds of subspecies, according to the International Union of Naturalists. The term Tabanus was coined by the ancient Roman scholar Pliny the Younger to refer to the animal, and it is currently used to refer to the genus as well. The American horsefly (T. americanus) is a species of fly found in North America. It may be found throughout the United States and Canada, from Kansas to New Hampshire and from Florida to Texas, as suggested by its particular epithet, which is It may also be found in the province of Ontario.


The black horsefly is also known as the dull black horsefly, and its name is derived from the Latin term for dull black.

  • There are several species of T. catenatus, including the gladiator, T. darimonti, T. nigripes, T. ochrogster, T. tuberculatus, T. proximus, T. eggeri, T. quinquevittatus, T. fairchildi, T indistinctus, T. zythicolor, and T. xanthogaster.

Horsefly Appearance

Horseflies are referred to as “trueflies” in some circles. As a result, they only have one set of wings and are equipped with balancing halteres that are located just below the base of their wings. Halteres are responsible for horseflies’ ability to do acrobatic maneuvers in flying.

Articles Mentioning Horsefly

Check out all of our amusing and thought-provoking animal articles. If you look closely at horseflies, you will see that they are large and have large compound eyes that can be vividly colored or display iridescence when viewed in certain lighting conditions. Males may be distinguished from females by the fact that their eyes are practically touching, but females’ eyes are apart. A ring surrounds the end of their antenna, which is otherwise hairless. In addition to having hairs on the fly’s head and thorax, which is the center section of its body, the fly’s wings are either transparent or either a hazy gray or brown color.

  1. Small changes in the shape of their heads, the pattern of veins in their wings, and color patterns on their bodies can help distinguish between different kinds of birds.
  2. The men have a single pair of mandibles and no maxillae.
  3. Hippocampal larvae or maggots are long and tapered at the head end, with the head having the ability to retract.
  4. They range in length from 10 to 30 millimeters and can be found in damp or moist environments.

The pupa is similarly between 10 and 30 millimeters in length and is brown and lustrous in appearance. Once through its shell, a faint silhouette of an adult fly may be made out. A horsefly sitting on the underside of a green leaf Photograph courtesy of Wong Gunkid/Shutterstock.com

Horsefly vs. Deerfly

Horseflies and deerflies are both members of theTabanidaefamily, and they are both known to attack people. Deerflies, as opposed to horseflies, are more prone to bite people than are horseflies. However, there are some notable distinctions between the two of them. Horseflies are significantly larger in size than deerflies. Horseflies are between a half inch and an inch and a quarter in length, whereas deerflies are between a quarter and a third of an inch in length, according to the National Wildlife Federation.

The deerfly’s antennae are long and thin in appearance.

Animals that are moving are exclusively bitten by deerflies, but horses are bitten by horseflies regardless of whether the animal is moving.

Horsefly Behavior

The vast majority of horseflies do not go very far from their place of birth, yet some can travel more than 40 kilometers. When they need to take a break, they can be found in the center of the road, on a path, or in low-hanging vegetation. The insects are diurnal, which means that they do not bite throughout the night and that they bite less on overcast, chilly, and windy days. They are drawn to lights, such as porch lights, and might congregate in large quantities to fly about them at certain times of day.

The majority of horseflies target the legs, ankles, or backs of the knees of their victim, whereas deerflies prefer the nape of the neck, the top of the head, and the shoulders of their prey.

Horsefly Habitat

Horseflies can be found in almost every ecosystem on the planet, with the exception of those that experience extremes of temperature or those that are extremely dry. It does need to deposit its eggs near bodies of water or in wet conditions, and it also need a habitat with enough animals to give adequate nourishment for the mother to raise her young.

Horsefly Diet

In between lapping blood, the female and the male consume nectar and other plant liquids to keep themselves nourished. Some horseflies are actually beneficial pollinators, and this is true of some species. However, in order for the female to procreate, she need a blood meal. When it comes to hunting for prey, the female horsefly is quite similar to the female mosquito. In addition to black fur or clothing, the carbon dioxide that the prey exhales as well as the warmth and texture of their body all attract her attention.

  • They will even eat the remains of an animal that has recently died.
  • If she is swatted away, she will at the very least make an effort to return so she may finish her food.
  • Horseflies are mostly solitary insects, however some attack in groups.
  • Horsefly maggots are also fierce predators that prey on other insects.

Frogs and toads are among the creatures that they will consume if they are tiny enough. Not only that, but the larvae appear to be poisonous, since prey is subdued after being bitten by one of the creatures.

Horsefly Predators and Threats

Horsefly eggs are utilized by parasitic wasps to nurture their own eggs, which is why they are called horsefly eggs. Tachinid flies and microscopic worms known as nematodes are the primary predators of maggots. They are also preyed on by birds and other animals, and they are susceptible to fungus. Horseflies that have matured are also devoured by birds. In spite of its frightening appearance, the soft-bodied, stingless horsefly have no natural defenses against anything that wishes to consume it.

Having rendered the fly incapacitated, she flies it back to the nest, where it will be devoured alive by her larvae.

What Eats the Horsefly?

Horseflies are preyed on by birds, wasp larvae, and other predators that prey on flies, among other things.

What Does the Horsefly Eat?

Horseflies consume nectar and plant juices, while female horseflies, of course, consume human blood.

Horsefly Reproduction and Life Cycle

Following their emergence from their pupae, horseflies begin reproducing almost immediately. It is possible that a male horsefly invasion is taking place, with males flying to hilltops and woodlands in search of females. When a guy goes by, she is pursued by him. In the event that she accepts him, they’ll mate for half an hour before feeding on her. This can only occur when the weather is warm and clear, as it is now. Some female horseflies only mate once throughout their lives, whereas others mate several times.

  1. She has the ability to lay anywhere between 100 and 1000 eggs at a time.
  2. After that, they fall into the water or into the damp earth, depending on the situation.
  3. After two weeks, the case breaks apart, and the fly drags itself out of the case by its own strength.
  4. The complete life cycle of a horsefly maggot, including molts and pupation, can span up to three years as it passes through several stages.

Horsefly Population

Due to the fact that there are over a thousand different species and subspecies of horsefly, it is reasonable to state that they are plentiful and do not appear to be in danger of extinction. Efforts to exterminate the species are fruitless. Attempts to manage horseflies have been made by humans for millennia, with varying degrees of success. Insecticides cannot be used in areas where horseflies and their larvae are present due to the environmental harm caused by insecticides. A horsefly that is determined to bite will withstand even the most effective insect repellents designed to keep mosquitoes away from the area.

  • Another option is to employ a trap, such as a carbon dioxide-based malaise trap or a Manitoba trap, to capture the horseflies.
  • View all 59animals that begin with HF When a horsefly bites you, she uses her cutting stylets to rip into your flesh, causing the wound to swell and get infected.
  • Telmophagy is the term used to describe this.
  • Wash the wound well and use a cold compress, taking care not to scrape the area.
  • In addition, unlike a mosquito, the female horsefly does not go to the bother of injecting an anesthetic into the bite so that you do not feel it.
  • Female horseflies can be considered omnivores since they consume nectar, plant fluids, and blood in addition to nectar.
  • Horseflies and houseflies differ significantly in a number of important ways.

Female horseflies require blood in order to receive the protein essential for reproduction, and the female horsefly is tenacious in her quest of it. A horsefly may be distinguished from a housefly by the fact that a female horsefly will actively pursue you!

How to Keep Horse Flies Away from Your Yard

Horse flies are well-known for their painful bites, which are caused by their scissor-like jaws. Female horse flies, like female mosquitoes, are attracted to your blood because it provides them with nutrition. (Male horse flies are attracted to nectar mostly.) A horse fly bite, on the other hand, will result in a loud “ouch!” unlike a mosquito bite, which may not be recognized until it begins to itch. If you have a problem with horse flies in your yard, follow these guidelines to help protect yourself, your family, and your pets (or livestock).

What Do Horse Flies Look Like?

As one of the biggest flies on the planet, they are reasonably easy to detect, yet they can be tough to thwart due to their size. In order to establish whether or not you have horse flies, look for the following features. Horse flies have extremely huge and robust bodies that range in length from 3-4 inches to 1-14 inches. A variety of colors are available, ranging from dark brown to grey to black. Their eyes are huge and can be either green or black in color.

Maintain Your Yard

Because horse flies like moist regions and hot temperatures, they can be seen in large numbers in pasturelands near creeks throughout the summer months. They prefer weedy patches and tall grass around dwellings because they can retain moisture and help to reproduce the humid pasture habitat that they adore so much. Horse flies may also be a nuisance for folks who spend their time at the beach or at the local pool.

Remove Garbage

Horse flies, like other fly species, will concentrate their efforts on waste in search of food. The lids of outdoor garbage cans should have a tight fit. Keeping your garbage in your garage may help to reduce the number of flies that fly over your yard.

Clean Up after Pets

Horse flies, like many other insects, are drawn to the excrement of domesticated animals. The summer months will necessitate more regular yard cleanups if you have a canine companion, otherwise you may find yourself with a horse fly infestation on your hands.

Burn CandlesTorches

If you’re hosting a backyard BBQ or other outdoor celebration, burning citronella candles and lighting torches will help keep horse flies away from your guests and prevent them from attacking them. Horse flies are attracted to the smoke and aroma created by citronella oil, so using it can help keep them away.

Kill and Prevent Horse Flies

  • Colour Colors: black, gray, and soft yellow
  • Size: ranging in length from 6 mm to 32 mm
  • Description A big, brilliantly colored compound eye and prominent mouthparts distinguish this enormous, stout-bodied creature with iridescent coloration. Some species have stripes on their abdomens, whereas others do not. They are excellent flyers and are capable of covering vast distances with relative ease.

Why do I have horse flies

The horse fly, as well as the closely related deer fly, feed on the sugar found in flower nectars. When they are right before laying their eggs, however, they bite and sucking the blood of bigger creatures, including humans, in order to obtain a “blood meal” that is necessary for egg development. Although deer flies prefer to bite deer and horses, horse flies prefer to bite horses; nonetheless, they will also bite other animals if they are given the opportunity.

How worried should I be about horse flies

Feeding on flower nectars provides sugar for the horse fly and its cousin, the deer fly. To get a “blood meal,” which is required for egg development, females bite and suck the blood of bigger mammals, including humans, right before laying eggs.

Although deer flies prefer to bite deer and horses, horse flies prefer to bite horses; nonetheless, they will also bite other animals if they are given the chance.

How can I avoid horse fly bites

The horse fly, as well as the deer fly, which is closely related, feed on the sugar found in flower nectars. To get a “blood meal,” which is necessary for egg development, females bite and suck the blood of bigger animals, including humans, right before depositing their eggs. Although deer flies prefer to bite deer and horses, horse flies prefer to bite horses – and vice versa – they will both bite other animals as well.

Other pests related to Horse flies

Our number one aim is to get rid of your insect infestation. If re-treatment is necessary, we will give it at no additional charge as soon as possible. Regardless of whether or not your expectations are reached, we promise a complete return of your service purchase.

Facts About Horse Flies

Horse flies (Tabanidae) are huge, aggressive insects that fly quite quickly. They are also highly spry flyers. Horse flies are among the biggest of all fly species, and there are around 3,000 different species of Horse flies in the globe. Females attack people and other animals (particularly horses and other livestock) in the hopes of obtaining blood meals for their young. Horse flies and Bot flies are referred to as “gadflies” in some circles. Horse flies might be a nuisance, but remember that you are not alone in feeling this way.

They were also a source of concern for the Vikings.

Continue reading for the most crucial facts about horse flies, as well as information on how to put preventative measures in place to keep you and your family safe from horse flies.

What Do Horse Flies Look Like?

Horse flies are available in a variety of colors ranging from yellowish-brown to dark grey to blackish in appearance, and they normally reach 3/4″ to 1.25″ in length. Their heads are disproportionately large in comparison to the rest of their bodies, and they are hairy all over, giving them a passing similarity to honey bees in appearance. They have just one set of wings, like all other genuine flies of theDipteraorder, which are delicately colored and covered with wispy dots, much like all other true flies of theDipteraorder.

Horse Flies vs. Deer Flies

Horse flies are frequently mistaken with Deer flies, which are also known to attack humans on a regular basis. Horse flies and Deer flies both have vividly colored eyes, however Deer flies are somewhat smaller than Horse flies. They are distinguished by the black stripes that run across their wings.

Where doHorse FliesCome From?

Aside from the polar extremes and few islands, such as Hawaii, horse flies may be found almost wherever on the planet, including the tropics. These fly prefer warm, wet environments where they may reproduce, although they can be found in a broad range of habitats, including deserts and alpine meadows, depending on the species. Horse flies are strictly outside creatures, and they do not feed or seek shelter indoors unless it is necessary.

You may come across one who has mistakenly walked inside your home through an open window or door, in which case a flyswatter or a dependable indoor and outdoor fly spray will make fast work of it.

Horse Fly Habits

Most of the time, these flies may be found in valley meadows near creeks and streams, where they enjoy higher temperatures and more moisture, as well as regions where cattle and people can be located outside. Horse flies are not simply attracted to the open air (especially near pools of water, like mosquitoes). They also love bright sunshine and are most common throughout the summer months, and they seek to avoid dark, shaded regions when possible. Horse flies do not emerge from their lairs at night.

Females are the only ones who bite, as they have powerful, incisor-like mouthparts, whereas males have weak mouthparts, as shown in the photo.

During their development, horse fly larvae live in aquatic or semi-aquatic settings, where they prey on other smaller organisms.

What AttractsHorse Flies?

Female Horse flies can identify humans and animals by their colors and motions, and they are drawn to bright items, warmth, perspiration, and carbon dioxide emitted by humans and animals, among other things.

Can Horse Flies Bite?

Female horse fly bites are extremely painful, but what’s worse is that these insects have the ability to transmit germs and blood pollutants from one host to another. They have the potential to make animals and people severely ill, and in unsheltered cattle, they can even cause growth rates and milk supply to be lowered. If the person or animal who has been bitten has an allergy, the consequences are more severe. Blood-stained horse fly bites on people can cause rashes, dizziness, weakness, and wheezing, as well as other symptoms such as headaches and fatigue.

Likewise, scratching will exacerbate the itching and other side effects of mosquito bites.

Will Horse Flies Bite Your Dogs?

In addition to being extremely painful, female horse fly bites have the potential to transmit pathogens and blood pollutants from one host to another. They have the potential to cause severe illness in animals and people, and in unsheltered cattle, they can even cause growth rates and milk production to be lowered. A bite victim who has an allergy will suffer more severe consequences. Blood-stained horse fly bites on people can cause rashes, dizziness, weakness, and wheezing, as well as itchiness and swelling (like a welt).

Because mosquito bites are itchy and have negative consequences, scratching will exacerbate these symptoms. In most cases, symptoms of a bite may subside within a few hours, but if an infection develops, seek medical assistance immediately.

TheHorse FlyLife Cycle

Female Horse flies deposit their eggs under gravel or plants in close proximity to a water source, but they do not need to be close to it. When the eggs hatch, the pale, spindly larvae crawl into a nearby body of water or moist soil, where they feed on tiny insects and even reptiles for the rest of their lives. When the horse fly larval stage is complete, it can continue up to a year, at which point the larvae burrow themselves into the earth in order to pupate. Horse flies mature after one to two weeks as pupae and another three to ten weeks as developing adults before emerging as fully fledged adults.

Helping Prevent a Horse Fly Problem Outdoors

Horse fly problems in suburban regions are less prevalent than in less-populated, rural locations, where there may be grassy, open fields and cattle in the vicinity. Ideally, pest control chemicals should not be utilized until all other options have been exhausted and the Horse fly problem has not been resolved. Citronella candles and ultraviolet bug zappers are two common cures for flies and other flying insects when used outdoors. Horse flies are not drawn to rubbish or animal corpses, but keeping your yard as clean of standing water as possible will help to keep them to a minimum (as well as mosquitoes, which are also attracted to standing water!)

Fly Killer Treatments

Products for Pest Control For spot-treatment of Horse flies, use a plant oil-based indoor fly killer such as Maggie’s Farm Home Bug Spray or Maggie’s Farm Flying Insect Killer, which are both highly effective. Plants despise flies and other insects just as much as you do, and the natural oils they create to defend themselves are incredibly powerful in killing and repelling insects of all kinds. If you want excellent personal protection against flies (and mosquitoes), use Maggie’s Farm Natural Insect Repellent, which is made from plant oils.

Always read and carefully follow the recommendations on the label of any pest control product, including those for storage and disposal.

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