Do Flies Bite?

Do Flies Bite?

The common houseflies that invade your living spaces every summer may be annoying (and a health risk) but they do not bite humans. However, several of its fly relatives do bite humans. It’s important to watch out for these species, as well as know what to do if you do get bitten.


While common houseflies are a considerable nuisance, they do not bite. This is because common houseflies (Musca domestica) have sponging/lapping mouthparts that are made for sucking up liquid, not puncturing skin. 

Houseflies liquefy their food and will eat anything ranging from fresh food and garbage to human and animal feces. This makes them a considerable health risk in your home because they carry harmful bacteria. When flies land on food or other surfaces in your home, they leave behind germs that can make you sick—so even though they don’t bite, they are still unwelcome guests.


Several species of flies do bite humans. Rather than venturing indoors like common houseflies, biting flies typically live outdoors near large animals like livestock or forest mammals. Biting flies feed on blood and resort to human hosts when animals are scarce or less convenient. Many biting fly species will travel miles in search of food, so if you happen to be in the crosshairs while walking around outside, watch out for these biting flies:


The stable fly (Stomoxys calcitrans) is also known as the biting housefly or barn fly. While they prefer to feed on the blood of horses and cows, stable flies also commonly bite humans and dogs. Stable flies are common in Florida, New Jersey, and off several lakeshores in the central states. They are similar in size to common houseflies but have distinctive black spots on their bodies that set them apart. Unlike most biting fly species, both male and female stable flies feed on the host’s blood. Their bites are painful.


Both of these flies are from the Tabanidae family. In both species, the females feed on the blood of humans and other mammals, inflicting a painful bite that often leaves the skin irritated. Horseflies and deerflies are found almost everywhere throughout the world. 

One easily identifiable difference between these two species is their size. Deerflies are about ¼ inches long, while horseflies are some of the largest biting flies, measuring over 1 inch long at times. 


These tiny grayish flies are a big nuisance to humans and animals alike. In order to suck host blood, biting midges inflict a sharp bite with a lingering burning sensation. Biting midges also transmit Blue Tongue virus, a serious livestock disease, in the United States.


Related to biting midges, sand flies are tiny flies found in sandy tropical climates that produce painful pinprick bites. Though not common in the U.S., you may run into these flies while on vacation. Sand flies also commonly carry the harmful Leishmania parasite.


Blackflies are found all over the world and breed in clean, running water. Several species of blackflies bite humans as well as other mammals and feed on their blood. These flies are relatively small—about ⅛ inches long—and are also known as buffalo gnats.


Typical fly bites resemble most other insect bites—redness and swelling of the skin, accompanied by a raised bump at the bite site. Many people develop welts and may see a white pimple-like center in the bite.

More serious bites cause rashes, blisters, scabs, and significant swelling. You may want to draw a circle around your bite in order to see if a reaction spreads. Consult your doctor for any concerning insect bites.


Most of the time when a fly bites you, you’ll feel a sharp pain, develop some redness or swelling, and then see symptoms fade over a few days. Like that of mosquitoes, biting fly saliva causes itchiness and skin irritation that subsides when left alone. 

If you’ve been bitten by a bloodsucking fly, it’s important to clean and treat the bite to avoid infection. Large biting flies like horseflies can leave puncture wounds that should be disinfected and bandaged as soon as possible. You may also want to take pain medication and apply a cold compress to the affected area if your fly bite symptoms persist. 

Many people have mild allergies to fly bites that cause itchiness and irritation. However, some people have serious allergic reactions to fly saliva that require medical attention. If you have any of the following symptoms after a fly bite, consult your doctor right away.

  • Shortness of breath
  • Tightness in the throat
  • Hives
  • Wheezing


While most disease transmission occurs between flies and animals, some biting flies also spread disease among humans.


One of the most notable diseases spread by fly bite is tularemia. Deerflies can spread tularemia—also known as “rabbit fever”—which causes swollen lymph glands, mouth sores, fever, and skin ulcers. If you are infected with tularemia, your doctor will likely prescribe a course of antibiotics to fight off this dangerous disease.


The other common transmission between flies and humans is the Leishmania parasite spread by sand flies (a relative of biting midges). When an infected sand fly bites a human, it spreads this parasite to its host. This disease causes skin sores that can take months (or even years) to go away as well as swollen glands. Leishmaniasis is a curable disease most often found in the developing world. 

While sand flies are not commonly found in the U.S., it’s possible to get bitten while traveling and then come home with leishmaniasis symptoms. 


Whenever you’re dealing with concerning pests, the experts at Joshua’s Pest Control can help. Our professionals train daily on pest identification, behavior, and elimination so we can bring reliable, effective services to every visit. 

For help getting rid of flies in and around your home, contact the friendly pest control experts at Joshua’s Pest Control today. We pride ourselves on high-level industry knowledge so that you can feel at ease in your home again.


Author Bio

Courtney Enzor has worked in the pest control industry for about a decade. From helping you build a fly trap to giving you the best tips for identifying various bugs, she loves answering all your pest-related questions and sharing her pest-related expertise through writing. At the end of the day, she hopes her content will help people avoid mishaps and keep families happy and healthy!