Gnat Bites: How to Tell If You Got Bit and Treatment Options

Written by Fern Damron
Updated: October 27, 2023
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Regardless of where you live, you’ve probably dealt with swarms of tiny biting gnats at some point. There are thousands of species of biting gnats and midges and over 600 of them are described across North America alone. They often appear late in the day or early in the morning and, when they’re ready to reproduce, leave nearby people and pets with annoying welts.

In this article, we’ll talk about why gnats bite, what their bites look like, and what to do if you’ve been bitten. In the end, we’ll talk about a few tactics you can employ to help avoid and prevent gnat bites in the first place.

Close up of a male biting midge, Ceratopogonidae or No See Um, on wood

A close-up shot of a male biting midge. These tiny insects are usually no larger than 1 or 2 millimeters in length.

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Why Do Gnats Bite?

Depending on the species, a gnat may or may not bite humans or other animals. Those that do bite belong to the family Ceratopogonidae. In general, gnats eat a variety of foods. Decaying fruits and vegetables, fungi, and plant nectar are a few popular choices. However, species of biting gnats like the buffalo gnat are similar to mosquitoes in that females must feed on blood as part of their reproductive cycle. To produce viable eggs, females need a strong source of protein to supplement their usual diet of plant sugars.

They collect the blood they need by using their scissor-like mouthparts to make shallow cuts in the skin. In the process, they release an anti-coagulant compound that prevents blood from clotting. This ensures that the gnat has free access to the blood of its target host. It is this salivary compound that causes familiar itchiness and allergic reactions.

Once they have taken the blood that they need to reproduce, the females will venture back to a body of water to lay their eggs. After the reproductive season has ended, adult gnat populations begin to die off.

What Do Gnat Bites Look Like?

Gnat bites often resemble those of mosquitoes. They are small, itchy, red bumps that may appear in clusters. Some people may experience a mild allergic response which causes localized pain, warmth, swelling, or fluid-filled blisters. These bites, although uncomfortable, are not usually cause for alarm.

Allergic Reactions and Anaphylaxis

Some people may experience more severe reactions, however. In some cases, sensitive individuals may experience a serious reaction called anaphylaxis. This reaction can be life-threatening and necessitates emergency treatment. Usually, the onset of anaphylaxis occurs between 20 minutes and 2 hours after the bite. Early Indicators include lightheadedness, coughing, wheezing, and tightness of the chest. Facial swelling, as well as swelling of the throat and tongue, are indicators of anaphylaxis.

Anaphylaxis must be treated immediately with a dose of epinephrine. If emergency medication is not available, seek immediate medical attention. Left untreated, anaphylaxis can be fatal.

Treatment Options

If you’ve got gnat bites, the best thing you can do is treat the discomfort associated with them. Because they present similarly to mosquito bites, treatment is often the same. The first and best thing to do is to wash the affected area with soap and water to help prevent infection. Then explore treatment options.

Many people reach first for over-the-counter anti-itch creams to soothe itchiness and irritation and prevent them from scratching. Antihistamines can help to manage symptoms of mild allergic reactions as well, like itchy hives or fever. You can use a cold compress to numb the skin and help decrease heat and swelling around the affected area.

If you know that you react severely to insect bites and stings, you should always carry emergency epinephrine with you when going outside. If you do have an anaphylactic reaction to a gnat bite, your most important treatment option will be on your person.

While you can avoid watery areas like lakesides and ponds to help prevent contact with gnats, it is best to employ multiple preventative measures — especially if you’re allergic.

©Patrick Jennings/

How to Prevent Gnat Bites

Gnats live in a variety of environments and can, at times, be difficult to avoid. While they often live in great numbers near wet areas like lakes and ponds, they are also likely to show up in your backyard. Avoid them if you can help it; but otherwise, the following tips can help you prevent gnat bites wherever you are.

  • Cover your skin. Gnats are often unable to bite through clothing. Closed-toe footwear like shoes or boots will protect your feet.
  • Wearing light-colored clothing can help avoid bites. Many gnats are drawn to darkly-colored objects.
  • Use your insect repellent of choice to keep the gnats away. Many experts recommend products that contain DEET.
  • If you’re spending time outside of your home in the morning or evening, try turning on a fan. Many species of gnats, like buffalo gnats, are not strong fliers and moving air can prevent bites. This can help with mosquitoes as well.
  • Create physical barriers when possible. Window screens and bug netting can effectively keep gnats out of your spaces.

Can You Catch a Disease Through a Gnat Bite?

It is highly unlikely to contract an illness or disease from a gnat bite, though it’s not impossible. Certain gnats can be possible carriers of certain germs, but cases of them transmitting to humans are rare. It’s also worth noting that if you don’t wash and treat a gnat bite, it could develop an infection, so always take care of apparent bites that may itch or be swollen. Below are some types of gnats with the diseases they could carry.

  • Biting Midges–Also called no-see-ums, these gnats could carry blue tongue virus which affects sheep and cattle.
  • Sand Flies–A bite from this gnat could possibly cause sand fly fever or cutaneous and visceral leishmaniasis, though very rarely.
  • Black Flies–Onchocerciasis, also known as River Blindness, could be transmitted by a bite from one of these flies in Africa and other tropical parts of the world.
  • Eye Gnat–This type of gnat has been know to cause pink eye.

The photo featured at the top of this post is © In The Light Photography/

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About the Author

Fern Damron is a writer at A-Z Animals who covers a variety of topics including plant life, gardening, and geology. They live off-grid in the Southeast U.S. and have been working to restore local Appalachian ginseng stands since 2020.

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