Why Are Horse Flies So Aggressive? (Solution found)

Why are horseflies so aggressive? Horseflies are known for their aggressive nature, which is due to their blood diet. The more time they spend around humans and other animals, the hungrier they get and the more aggressive they become when looking for food.

  • Horseflies are aggressive because they’re hungry! Or, more accurately, their babies are hungry. Only the female horsefly bites, and she does so to obtain protein from blood to form and grow her eggs.

Why do horse flies bite so hard?

An anticoagulant in the fly’s saliva then prevents the blood from clotting as the insect sucks up its meal. While mosquitoes release a mild anaesthetic, horseflies don’t – which is one of the reasons their bites are so painful. The fact that they cut into the flesh rather crudely only adds to this pain.

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.

Are horse flies aggressive to humans?

Yes, horse flies are considered to be dangerous to both people and animals. Female horse flies are aggressive and their bites are very painful because their mouthparts tear at the skin of their victim instead of simply piercing it.

How do you keep horse flies from biting?

How to Prevent Getting Bitten by a Horsefly

  1. Wear long sleeves, long pants, and closed-toed shoes when you’re outside.
  2. Wear light colors (horseflies are drawn to darker colors)
  3. Don’t wear any perfume (scents attract these critters)
  4. Avoid walking through long grass.
  5. Apply insect repellent before you head out.

Why do horseflies chase you?

Horseflies bite to ingest blood which is rich in protein. The protein is needed to develop their fertilized eggs. And yes, horseflies will chase you down to get their meal.

What happens if a horse fly bites a horse?

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. If infected, a horse may experience a fever, hemorrhaging, and general illness.

What are horseflies attracted to?

These flies apparently are attracted to such things as movement, shiny surfaces, carbon dioxide, and warmth. Once on a host, they use their knife-like mouthparts to slice the skin and feed on the blood pool that is created.

How painful is a horse fly bite?

A horsefly bite can be very painful, with the skin often turning red, itchy and raised. Depending on the bite, you may also experience a raised rash (known as hives or urticaria), and, in some cases, dizziness.

Do horse flies lay eggs in your skin?

Like female mosquitoes, female horse flies require a protein meal to produce the eggs that will grow into the next generation of horse flies. Using these tiny blades, horse flies cut open their victim’s flesh and drink from the blood that pools in the wound. These bites can result in irritation and swelling.

What to do if a horse bites you?

Your horse needs to understand that biting is bad. If your horse goes to bite you, immediately send them out on the lead at a working trot or canter. Have them go on the circle a while to communicate your point. Don’t let them stop on their own; they stop when you ask them to.

Do horse flys 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.

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.

Can you swat a horse fly?

SWAT Fly Repellent Ointment is approved for use on horses, ponies and dogs too!

Why do flies bite ankles?

Sensors on their antennae help the mosquitoes locate our breath, Ray says. “They look for plumes of carbon dioxide, which we humans create when we exhale. And they’ll start moving toward those plumes.” They may target our feet and ankles because we’re less likely to notice a mosquito biting us there.

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?

Horse flies reach a maximum length of 12 to 14 inches when fully grown. Their strong bodies range in hue from gray to black, and their wings are clear or somewhat clouded in appearance according on their species. Equine flies have huge, vivid green or purple eyes and relatively short antennae, which distinguish them from other species of fly. Females have specialized blade-like mouthparts that they use to slice the skin of a person or an animal, as well as spongy mouthparts that they use to suck off the blood from the skin.

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.

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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Horseflies: Why they’re the worst and what you can do about it

What causes their bites to be so painful? Why aren’t they going to die if you smack the living daylights out of them? Today, we’ll address some of your most pressing horsefly questions. Does the presence of horseflies in the animal realm serve a purpose, or were they simply sent on this planet to make me and my horses miserable? That is an excellent question. Typically, when I think of horseflies, I think of the large, venomous bullet-shaped monster-bugs that appear to take pleasure in devouring my horse alive, but there are around 4,500 different species that are members of the horsefly family (Tabanidae).

  • Other reasons to despise them include: It is possible for 20-30 horseflies to drain about a third of a pint of blood from their victims in as little as six hours if they are not managed.
  • Horseflies are something that this individual absolutely, positively, positively despises: What is it about their bites that causes such excruciating pain?
  • The larger the hole, the greater the amount of blood they may absorb.
  • When a horsefly was eating a hole in his arm, this brave guy captured it on film: “I’ll hit one extremely hard, but it only gets disoriented for a minute and then comes back for more.” WHY IS IT NOT JUST DIETING?!?!?
  • They are not easily discouraged from attacking, and they will even pursue their chosen prey after they have been caught.
  • Unfortunately, we are unable to assist you.
  • To keep them at bay, avoid forested, moist locations such as streams and ponds.

They are most active during the warmest part of the day and like to stay out of the sunlight. The horsefly season in August and September was a nightmare on the farm I used to operate, and the following were some of our most successful horsefly survival strategies:

  • When feasible, ride and turnout should be done in the mornings and evenings. Fly spray and fly predators are fine places to start, but during horsefly season, a fly sheet is very essential. When riding and working around your horse, always be on the lookout since you never know when it could buck, kick out, or whip its head around to get rid of an intruder. Horseflies are drawn to dark hues, so keep this in mind while selecting your clothing.

Alternatively, you may follow the example of this young rider: Retaliate by launching an attack! Wishing you the best of luck, and Happy Riding! – Please give us more! If you like this post, you may be interested in. Do you enjoy HORSE NATION? Keep up with the latest news, analysis, and hilarity by “liking” us on Facebook!

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.

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Horse Fly Habits

Most of the time, these flies can be found in valley pastures near creeks and streams, where they prefer higher temperatures and more moisture, as well as areas where livestock and humans can be found outside. Horse flies are not only attracted to the open air (especially near pools of water, like mosquitoes). They also prefer bright sunlight and are most common during the summer months, and they tend to avoid dark, shady areas when possible. Horse flies do not emerge from their lairs at night.

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

Women (again, as is the case with mosquitoes) bite both animals and humans in order to obtain protein in the form of a blood meal, which they use to fertilize eggs. During their development, horse fly larvae live in aquatic or semi-aquatic environments, 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 humans 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?

The scissor-like mouth of the female Horse fly can inflict painful bites not only on humans, but also on your dog. Even though the effects and minor irritation are only short-lived, your dog is still at risk for the same danger that comes with all biting pests: the spread of bacteria and other blood contaminants from the female Horse fly’s saliva. In addition to the belly, legs, and neck, larger dog breeds are the most prone to Horse fly attacks. The most common regions where dogs get attacked are the legs, abdomen, and neck.

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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TryMaggie’s Farm pest control solutions for efficient fly control in your house that has been scientifically proven and is safe for your family and the environment.

In order to be the most effective, our plant and mineral-based treatments are created by scientists and experienced pest control specialists.

Horse fly population higher than normal, hard to control

In addition to inflicting devastating wounds on animals, horse flies may also transmit illnesses to them. Livestock should be removed from infestation places as soon as possible to alleviate and protect the animals. Chemical treatments have demonstrated limited efficacy in controlling horse flies, and many of the products available are not labeled for use on horses. (Photo courtesy of Texas A&M AgriLife Communications/Katie Hancock)

STATION OF COLLEGE – A Texas A&M University AgriLife Extension Service specialist says high populations of horse flies, a persistent and difficult biting insect to eradicate, have posed issues for livestock producers this year across the state’s cattle ranches. Dr. Sonja Swiger, an entomologist with the Texas A&M AgriLife Extension Service in Stephenville, said reports of horse fly infestations are at levels she hasn’t seen before in her 11-year career. “It’s been the worst year I’ve ever experienced,” she remarked.

  • Swiger predicted that numbers will begin to decline since temperatures had increased to uncomfortable levels in recent weeks.
  • According to her, despite their name, horse flies are not host-specific and will feed on a variety of opportunistic human and animal hosts.
  • Horse flies, on the other hand, cut the host and drink the blood that pours from the incision, unlike mosquitoes.
  • Tabanus americanus, the female horse fly, is a blood-sucking insect that may be obstinate and aggressive.
  • (Photo courtesy of Dr.
  • Women will travel from cover to host once a day to forage for carbohydrates in the form of nectars and honeydew, but males will only do so once.
  • Laying eggs in shaded, semi-aquatic to wet locations, such as along the borders of ponds or water tanks, is common practice for this species.
  • “The larvae are maggots, but they have the appearance of maggots on steroids,” says the author.


Horse flies are tough to control, according to Swiger. However, there are a few things that may be done to assist limit the amount of animals and relieve animal bites. According to Swiger, there is no published data focusing on the effectiveness of pours aimed to reduce the number of horse flies in a certain area. However, pyrethroid, and particularly synthetic pyrethroid-based pours, have been demonstrated to give brief relief in some cases. Furthermore, the majority of synthetic pyrethroid products are not labeled for use in horses.

  • “Permethrins may be effective, but the alleviation will be limited,” says the doctor.
  • Swiger believes that horse fly traps that are particularly developed for horse flies can help to lower the quantity of horse flies in contaminated regions.
  • “As part of a research project, we captured 350 horseflies and 200 deerflies during a 10-week period in two counties.
  • We just don’t have enough evidence to determine how beneficial they are at this time.” Swiger raised the issue of anthrax as another potential danger associated with higher-than-normal horse fly populations.
  • Despite the fact that horseflies have a range similar to that of most flies (between 5 and 10 miles), the majority of fly populations remain quite near to the nesting habitat from where they originated, according to the researcher.

” In the absence of conclusive evidence, we cannot rule out the possibility that it is linked to higher-than-average horse fly populations, but it is something we would like to understand more about. -30-

6 Tips for Avoiding Horse-Flies While Running — Trail Roots

It’s already summertime! While it may not be the first thing that comes to mind when thinking of heat training, attempting to avoid the vengeance of a horse-fly is something that many trail runners have experienced. Horse flies attach to your clothing or your head, and then they prefer to take a large piece off of your flesh with their teeth. It begins off as a little itch that lasts for a split second before you realize you’ve been bitten by a dreadful horse- fly. Then it’s too late, and they’ve snatched a good bite out of you.

  • If you want to avoid horse-fly bites on your next trail run, here are a few things you can do to prepare.
  • You can also use Deet, which has been shown to be effective in repelling mosquitoes.
  • If you want to give your garments even more power, you may spray them with permether, which is a natural insecticide.
  • Because of this, horse-fly traps are frequently painted blue.
  • Alternatively, you can put sun sleeves on your arms, which will provide additional protection from the heat and horse-fly bites.
  • Wearing a buff or cap over your neck and head will assist to keep them off your skin and away from your eyes.
  • This should be of assistance.

Horse-flies are drawn to bodies of water, where they lay their eggs and raise their young.

It is difficult to run without moving or producing heat.

Despite the fact that I am aware of this, it does not prevent me from increasing my pace in order to dodge their attack.

6)If you are in close proximity to a road I’ve discovered that transitioning from a trail run to a road run brings me out into the open, where the horse fly seems to disappear rather soon.

Horse-fly bites, while irritating, are generally not dangerous to the human body.

As a side note, you will find that some pathways and parts of town have a higher concentration of horse-flies than others.

You’ll begin to recall which paths are the most challenging.

It is possible that fleeing from an one horsefly or a swarm of them may convert your nice easy trail run into a training day! If you have any horse-fly prevention strategies that we didn’t include, please share them with us in the comments section. Summer trail running wishes to you.

Strafing Horse Flies

Originally published on In the midst of photographing willow pinecone galls for a BYGL Alert today, I was repeatedly attacked by an insanity-inducing horse fly (Tananusspp.). These hefty flies are members of the Tabanidae family, which is the biggest family of bloodsucking insects in the world, with over 4,500 horsefly species known to exist around the planet. In Ohio, there are various species that range in size from 3/8″ to 1 1/8″ in length, depending on the species. T. abdominalis was the frenzied fly that was buzzing about my head.

  1. That’s what I dubbed it, at the very least.
  2. Women are the only ones who bite, as they require blood meals in order to be able to create eggs.
  3. After opening the cut, the female injects saliva that has anticoagulant qualities, and she subsequently laps up the free-flowing blood that has been released.
  4. Equine flies are equipped with unique eyesight that helps them to detect heat; in fact, they employ thermal imaging to identify their hosts.
  5. The group’s collective vision helps them to efficiently home in on huge, delicious, warm-blooded creatures like as cows, deer (especially in the winter), photographers (especially in the summer), and of course, horses.
  6. for the sake of the flies The last thing on the flies’ minds is their rear ends, which is the last thing on their minds.
  7. If at all possible, stay away from horse fly habitat.
  8. If you are unable to avoid their habitat, plan your actions so that you do not come into contact with the flies.
  9. As a result, nighttime pool parties will no longer be plagued with horse flies.
  10. Horse flies, on the other hand, make a loud, buzzing sound while they fly, unlike the majority of flies.
  11. Keep in mind that horse flies are drawn to moving objects, so refrain from running!

Finally, while insect repellents containing DEET or picaridin may offer some protection against horse flies, these insects are extremely adept at locating bare skin. Long sleeves, long trousers, and neckerchiefs can all be useful in keeping the flies at bay.


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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.

  1. Horseflies may be found all across North America, including Alaska.
  2. Some localities, particularly during the summer months, are plagued with horseflies, which are virtually inescapable in some areas.
  3. They prey on big creatures such as people, dogs, and, of course, horses, among other things.
  4. They’re also drawn to carbon dioxide, which makes sense.
  5. If you’ve ever had the impression that a horsefly was out for vengeance, you could be correct.
  6. 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.
  7. 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 and Deer Flies

|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.
  9. 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.


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. In order to pupate and eventually emerge as adults, mature larvae must crawl to drier locations.


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.


Horse flies and deer flies may be a real annoyance when they congregate near swimming pools. They may be drawn to the water by the gleaming surface or by the movement of the swimmers in the water. There are currently no viable recommendations for addressing this issue. Permethrin-based sprays are approved for use on animals and horses, according to the label. Because these pesticides are extremely unpleasant to the flies, they are forced to flee nearly soon after landing on the surface. Frequently, the flies do not come into touch with the pesticide for long enough to be killed, and as a result, they continue to be an irritation.

It is possible that repeated applications will be required.

In addition, pyrethrin sprays are effective, although their effectiveness does not continue as long as permethrin.

In the daytime, if animals have access to shelter, they will be able to avoid the relentless onslaught of these vexing pests.


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 Control: Get Rid of Horse Flies in the House

  • A horse fly’s body can be anywhere between 12 and 14 inches long depending on its size. Color: They are either black or gray in appearance. Eyes: People with huge, dazzling green eyes are common. Antennes: Horse flies all have antennae that are shorter than the length of their bodies


The female horse fly, which feeds on blood, has blade-like mouthparts that cut tissues and blood arteries, causing blood to flow to the wounds they produce. Females then soaking up blood with their sponge-like mouthparts is what they are known for. Males solely eat on pollen and nectar, and their mouthparts are identical to females’, but considerably weaker.

Horse Fly vs. Deer Fly

Horse flies and deer flies are closely related, and both are members of the Tabanidae family. The two most distinguishing characteristics of them are their total size and the shape of their wings. Horse flies are often significantly bigger than other species, with a stouter body and a very massive head with extremely huge eyes. When it comes to their wings, they are often transparent or hazy, whereas deer flies have black bands or patches across their wings.


While male horse flies feed on pollen and plant nectars, female horse flies are aggressive blood feeders, whilst female horse flies do not.

Finding Prey

When it comes to finding hosts, female horse flies employ a combination of chemical and visual signals in the same way that other blood sucking insects do, such as mosquitoes. A long-range indication provided by warm-blooded animals attracts horse flies from a distance, whereas visual cues such as motion, size, form, and dark color attract horse flies from a shorter distance, according to the National Horsefly Association.


They hardly seldom bite close to the head. In addition to animals of practically all sizes, horse flies also have a wide range of hosts that include humans and their pets, as well as cattle. If a female horse fly is interrupted while attempting to feed, she will fly away but immediately return to bite another host, or she will proceed to another host to take a whole blood meal from that host.

Horse Fly Bites vs. Deer Fly Bites

Large, non-moving creatures are frequently bitten on the legs or torso by female horse flies. Deer flies, on the other hand, attack moving hosts and tend to target high-up on the body, such as the head or neck, to feed.


When someone is bitten, they may experience the following symptoms and bite reactions:

  • The bite area will swell and become itchy, then the swelling will subside. Itching and scratching of bite wounds that persists for an extended period of time and can result in subsequent bacterial infections if the bite is not cleaned and sanitized
  • The fact that horse flies inject anticoagulant-containing saliva while feeding on humans increases the risk of significant responses, particularly among those who are strongly sensitive to the anticoagulant chemicals. An itchy rash all over the body, wheezing, swelling around the eyes, swelling of the lips, and dizziness or weakness are all possible symptoms.

ReproductionLife Cycle

Horse fly growth areas include freshwater and saltwater marshes and streams, wet forest soils, and even rotting wood that has soaked up moisture from the environment. In most cases, females lay their egg masses on damp soil or vegetation that overhangs bodies of water. Larvae are active in organic stuff that is damp or wet, and they have a similar appearance to house fly maggots. Depending on the species, horse flies have anywhere from 6 to 13 larval stages. The pupal stage begins in the spring after the last larval stage has completed its overwintering period.

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Fertile females will deposit their eggs on the undersides of leaves, and the larvae will hatch out and drop off the leaf in around 2-3 days after the eggs have been laid.

The majority of horse fly species produce just one generation each year, but some can take up to two years to complete their life cycle, according to the CDC.

Horse Fly Larvae vs. Deer Fly Larvae

During field study, researchers discovered that horse fly larvae prey on midges, crane flies, and even other horse fly larvae. As a result of their cannibalistic tendencies, horse fly larvae are typically seen living in isolation. Deer fly larvae, on the other hand, tend to congregate in large numbers. Pupae do not consume food. When it comes to producing viable fly eggs, female horse flies require a blood meal to be successful. A female can lay anywhere between 100 and 800 eggs every year.


Horse flies are present in nearly every region of the United States, and there are more than 160 different species to be found.

Prevention Tips

However, even the most potent insect repellents are only somewhat successful in keeping insects away. A better alternative for prevention is to cover and protect exposed areas of the body in order to lessen the probability of being bitten by horse flies.


However, even the most efficient insect repellents are only somewhat effective in most situations. A better alternative for prevention is to cover and protect exposed areas of the body in order to lessen the probability of being bitten by a horse fly.

5 Incredible Horsefly Facts!

  • However, even the most efficient insect repellents are only somewhat effective. The most effective method of preventing horse fly bites is to dress and cover exposed areas of the body.

Horsefly Scientific name

Insect repellents are useful, however even the most efficient repellents are not very effective. A better approach for prevention is to cover and protect exposed areas of the body in order to lessen the chance of horse fly bites.

  • 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.

  • 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.
  • The men have a single pair of mandibles and no maxillae.
  • Hippocampal larvae or maggots are long and tapered at the head end, with the head having the ability to retract.
  • 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?

Insects such as horsefly larvae and other predators that prey on flies prey on horsefly.

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.

  • She has the ability to lay anywhere between 100 and 1000 eggs at a time.
  • After that, they fall into the water or into the damp earth, depending on the situation.
  • After two weeks, the case breaks apart, and the fly drags itself out of the case by its own strength.
  • 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

Following their emergence from their pupae, horseflies begin reproducing immediately. If there appears to be an invasion of male horseflies, it is possible that they are searching for female horseflies on hilltops and in forests. After passing by, a guy begins chasing her down. Then they’ll eat for half an hour after they’ve mated for half an hour. When the weather is warm and sunny, this is the only time this happens. For some female horseflies, this is their last opportunity to mate throughout their lifetime.

Depending on the season, she may lay between 100 and 1000 eggs at a given time.

After that, they fall into the water or into the damp earth, depending on the weather.

After two weeks, the case breaks apart, and the fly pushes itself out of the case on its own own.

Male horseflies are often the first to emerge from their eggs. With molts and pupation, the horsefly maggot’s full life cycle can span up to three years, depending on its size. The mature horsefly, on the other hand, only lives for a month or two at a time.

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

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