How To Identify Biting Flies And Protect Yourself

Obviously biting house flies do so because they require the fats and the protein present in a host's blood as they are essential for egg development in the lifecycle of biting flies with some species even outright feeding on it. This causes them to attack humans and other animals with impunity seeing them as nothing but food sources.

And that's not only all as some of these biting flies even transfer disease through these feeding habits. There are many species of biting flies each with their own ecology and habitats that you might encounter, here are some of the most common species:

The deer flies are one of the most prevalent fly that bites especially during spring, they start their life as aquatic maggot-like larvae emerging from trails near streams, lakes, ponds, marshes, and swamps. As a juvenile, they may either eat small animals, detritus, or any other rotting organic matter.

This gives plenty of food sources for the larvae until they develop into adult flies. Unlike their moniker, despite being named deer flies, they won't discriminate between deer, other animals, and humans.

Appearance

Deer flies are medium-sized flies and are approximately 1/4 inch long which doesn't make them any different from your typical housefly, however, they are typically yellow-brown and have dark black bands on their wings which makes their identification easy.

Some species of deer flies also have distinctive iridescent green eyes which can be useful in diagnosing and avoiding these flies.

Bites

They have scissor-like mouthparts that cut into the skin and cause blood flow that the fly suctions. They wait on plants in shady areas during the day waiting in ambush until they see or smell something that they can feed on.

They can also transmit tularemia disease also known as rabbit fever to humans.

Horse flies are essentially larger upgraded versions of deer flies, they are significantly larger with most of them being an inch or longer. They are strong and fast fliers that feed on the blood of livestock and other animals.

Their larva thrives inside water or in warm and wet moist locations where they prey on other insects and migrate to dryer soil conditions as they grow in order to undergo pupation. Luckily this entire process takes them 2 years so they can be rarer than other types of flies.

Appearance

Its size isn't the only one where the horseflies deviate from the deer flies as unlike the deer flies which are yellow, horse flies are either entirely black or light brown with shiny green eyes which according to an excerpt have given them the nickname of greenheads.

Due to their strong wings, they are exceptionally harder to deter through the use of air currents and zappers, plus since they have a tendency to swarm, they can also end up smothering the cattle animals that they attempt to feed on.

Bites

Biting horse flies use their powerful serrated mandibles to slice into the skin when they bite which causes severe pain and swelling. In fact, the large size of a horse fly combined with the intensity of their bites, has come to make their bites be considered the most painful biting fly bite.

Luckily despite their painful bites, they do not transmit any diseases to humans, unlike other biting flies. Although they do still have anticoagulants in their saliva so allergic reactions can still be expected if not made worse.

Stable flies are aptly named because they primarily feed on livestock and thus are most commonly found inside stables. They are typically found near the coastal areas that border the neighboring farmlands as their eggs are laid in piles of rotting vegetable matter.

Once their eggs hatch inside haystacks, grass clippings, manure, or shoreline vegetation, the maggots feed on these rotting matter before becoming a fly. When these flies hatch in late summer and early fall, they have been noted to fly as far as several miles just to bite livestock, people, and pets. 

Appearance

The stable flies can look similar to houseflies but they have a key difference, the difference between adult stable flies have a mounted needle-like proboscis on their head which is uncommon on flies and helps them suck blood. 

The fly can become about 1/4 inch long with four dark stripes on its thorax. They aren't as small as midges and mosquitoes so luckily they shouldn't be able to get through your insect window screen easily.

Bites 

Although their bites are not as annoying as midges or a horse fly, they bite typically early in the morning or late afternoon rather than at night and target the ankles to inflict a sharp stabbing pain. 

Stable flies can carry parasites such as stomach worms, and nematodes while also transmitting some diseases to humans such as anthrax. 

The sandflies are related and physically very similar to the non-biting drain flies, however, that's all where the similarities end as the sandflies are capable of preying on not just mammals but also reptiles. 

Their larva are tiny and worm-like despite being a fly and are mostly found in decaying plant matter, moss, or mud which can make stagnant water or seasonal rain result in an especially massive uptick in their population. 

Appearance

An adult sandfly is less than 1/8th of an inch in length with long legs and wings that form a "V" shape while the flies are at rest. Although sandflies are very hairy with a distinct wing shape, some can also confuse them due to there being multiple species of sandflies due to which they can be brownish, silvery-brown, or gray.

However, almost all of these species turn reddish after sucking on blood. Sandflies are very weak fliers, unlike other flies that are easily capable of covering 5 miles as sandflies can rarely cover 0.3 miles in a day.

Bites 

Sandflies are nocturnal and thus most sandfly species feed on mammals and reptile blood at night. Their pain is especially noted to be extremely painful due to their proboscis which damages the skin and provokes an immediate histamine response from your body.

Although most species of sandflies don't spread any diseases, some species can transmit diseases such as leishmaniasis also known as kala-azar and Toscana virus to humans making sandfly prevention a critical goal for health safety.

Snipe flies are close relatives of deer flies but unlike the deer flies, they do not reproduce near rivers and creeks but instead typically live in damp places of highly forested areas. Furthermore, they can also be found near forested areas of higher elevations in some states which makes their habitat unique.

Unfortunately, it is also due to this reason there isn't much studied and known well enough about the snipe flies as much as the other types of livestock-threatening flies. 

Appearance

They are typically dark-colored which provides a perfect camouflage in the forests and are typically 1/4 of an inch along with a rounded head, tapering abdomen near the posterior, and long legs.

This description can make them sound like they could easily be mistaken as mosquitoes but they are bulker with a fuzzy thorax, larger compound eyes as well as the iconic dipteran housefly wings. 

Bites

There are multiple species of snipe flies and while most of them feed on other insects such as aphids, however, some species of snipe flies do bite humans and feed on the blood of mammals.

Snipe flies may bite vigorously and cause irritating bites if they find prey, luckily they do not transmit any diseases and poses no risks to human health, at least not in the same way as posed by black and horse flies. 

Often found primarily in the southeastern US, the yellow flies prefer secluded and shaded areas with plenty of forests and bodies of water. They are most active from late spring to late summer but due to the warmer tropical areas they can be found in, some of them might also be present until late fall. 

Yellow flies are closely related to deer flies as they both belong to the Tabanidae family. However, unlike their deer or horse cousins, yellow flies can be said to be a menace as they are the only fly to actively pursue and bite you indoors. 

Appearance

Adult yellow flies are slightly longer than 1/4th of an inch with yellow bodies. They have mid, hind, and forelegs that offer a black contrast to their yellow bodies while their eyes are a greenish-blue hue with purple bands. 

Bites

Bites carried out by a yellow fly will result in severely large swelling and itching. Although the flies themselves do not transmit any diseases themselves, the bites if not cleaned and treated properly could result in an infection such as Stalph infection.

Since yellow flies are active during afternoons or on cloudy days, they are harder to avoid than nocturnal biters so you should always be wary when being in the outlands of the South.

Black flies just like the previous flies love moisture and thrive around rivers or creeks so luckily they shouldn't be close to most urban and sub-urban settlement areas. Their larvae are often found attached to submerged stones for improved protection against their natural aquatic predators such as invertebrates and browsing fish.

They are capable of flying up to 10 miles away in search of blood or mates. Although they are capable of making their homes in most parts of the United States, proper management techniques should be able to mitigate any potential habitats.

Appearance

A black fly’s most distinguishing feature is its humped back which can be seen when viewed up close or under a microscope thus they are also known as humped back flies or buffalo gnats.

For something that's nicknamed as a buffalo, they are no more than 1/8-inch long so it's obvious that their nickname arises from its juvenile's amphibian nature. 

Bites

Biting black flies found in the United States do not transmit any disease to humans, however regardless of that injuries resulting from black fly bites can often threaten the lives of people and livestock when bitten in large numbers in late spring to early summer as they often tend to attack the head area.

This can result in wounds that are slow to heal, considerable swelling itchiness, and bleeding as well as severe allergic reactions from their anti-coagulants so, buffalo gnat bites should be treated properly.

The louse fly also known as keds belongs to the parasitic family Hippoboscidae and has several species that occur in both winged and wingless forms. Regardless of this shift, they are still considered under the Diptera family of flies.

Each female louse fly produces up to 20 larvae at the rate of about one per week. They are obligate parasites unlike other flies so, they can die of starvation if separated from their host for more than several days as they won't be able to sustain themselves on plant nectar.

Appearance

Louse flies are difficult to characterize due to their huge variance across several species of louse flies, however, their most common characteristic is piercing mouthparts that are used to such blood from warm-blooded animals. 

Some are dark brown, black, or even orangeish not dissimilar to lice, hence they can also be called "flying ticks". Furthermore, they are generally flat in shape and have a leathery appearance which makes them distinctive from most other flies.

Bites

Fortunately, the good news is although there are many species of louse flies that feed on birds and mammals, such as sheep, deer, and pigeon louse fly, there is no such fly that specifically targets humans. 

It might be possible for humans to be bitten by louse flies that fell off a pigeon, it is generally harmless and they would find the human skin an uncomfortable environment which leads to them eventually going away. 

Biting midges aren't too different from other flies in that they are also found near the coast in moist sand, soil, rotting wood, and vegetation. Their larvae thrive easily in the mud and sometimes are even found swimming freely in infested waters but what's even worse, they are also capable of breeding near salt marsh areas.

Midges are weak fliers and are highly susceptible to air currents, thus most only emerge commonly on still days. It should also be noted that all midges belong to the chironomidae family but not all midges are biting flies. 

Appearance

This is where the similarities with other biting flies end as midges rarely grow any larger than 1/32th of an inch in length which is even smaller than a mosquito, hence due to their size they're also known as no-see-ums, gnats, and punkies. 

Their tiny size allows them to penetrate through the doors and windows through the window screens, making them one of the most pervasive biting flies as they can also avoid the wire mesh in zappers. This makes them a menace along the shores of oceans, ponds, lakes, and rivers.

Bites

Their small size allows them to sneak through and leave you with surprise 'mystery bites' where you will be itching but the culprit is nowhere to be found. When no-see-um bites they also inject saliva which can cause an allergic reaction with itching and swelling.

Fortunately biting midges do not feed on human blood and both the male and female adult midges sustain themselves on plant nectar, instead, they only come for a blood meal when it's time to produce the eggs which is better than being plagued the entire season.

Tsetse flies are large biting flies that inhabit most of tropical Africa, they are similar to the louse fly in that they are an obligate parasite that sustains itself by feeding on the blood of vertebrates which highly increases the chances of getting bitten by a tsetse. 

Although tsetse is not found in America, people should still commit them to memory, especially vacationers as disease spread by a tsetse fly has a 100% mortality rate should it go undetected and untreated.  

Appearance

The most distinctive feature of tsetse flies is that they are distinguished due to their forward-facing proboscis on the head which is incredibly thick and is capable of puncturing skin.

They are as large as 1/2 of an inch in length with a rather drab yellowish-brown to dark brown appearance. Furthermore, they fold their wings over each other while at rest which immediately makes them distinctive from all other types of flies.

Bites

When a tsetse bites, it gives a sharp stinging sensation that subsides quickly. Although tsetse flies can be a vector of sleeping sickness, only infected tsetse flies are capable of spreading it. 

Thus, their bites can generally be harmless unless people suffer from a severe allergic reaction to its anti-coagulants.

It's obvious that the best way to eliminate bites from flies is to reduce their overall population, it doesn't matter how good the anti-pest screens, pesticides, or repellents are, they are in the end all reactionary measures and an increase in insect population and genetic mutation can overwhelm most of these measures.

So what's the best way? Most of the biting flies need water or some sort of damp environment to lay eggs so you should eliminate any stagnant still standing waters in the landscape, if that isn't possible you should introduce the natural fly predators such as fish into the lakes and ponds.

Make sure to also remove any trash and rotting organic materials followed by a timely cleaning and disposal of house food waste. These measures are universal and also help to get rid of cluster flies and other non-biting flies that spread pathogens.

No, common flies do not bite people in fact, fly bites are not that common, according to a 2023 study published in StatPearls, mosquitoes made up 90% of the plausible insect bites, thus, bites from the dipteran family of flies are already a rare occurrence in itself.

However, despite their rarity dipteran flies such as a horse fly bite can still occur however most of the common flies present in the household are all as you guessed it, houseflies that do not have the capability to bite nor the propensity to do so. So as long as you're indoors, you should not encounter biting flies.