How Do I Know What Bug Bit Me?

Medically Reviewed on 6/2/2021

bug bites
Your symptoms can help you identify what bug bit you

A bug bite can be irritating and cause pain, itching, swelling, redness, inflammation or blisters. But how can you tell what bit you? Your symptoms may provide clues:

  • Mosquito bites: A mosquito bite is a small, round, puffy bump that appears soon after being bitten. The bump will become red, hard, swollen and itchy.
  • Fire ant bites: Fire ants are aggressive, red or black venomous insects with a painful, stinging bite. Bites appear as swollen red spots that develop a blister on top. Stings burn, itch and last up to a week. They may cause a dangerous, severe allergic reaction in some people, resulting in swelling, generalized itching and difficulty breathing.
  • Flea bites: Flea bites are usually in clusters and located on the lower legs and feet. The itchy, red bumps are surrounded by a red halo. Symptoms begin immediately after being bitten.
  • Bed bug bites: Bed bug bites often cause an itchy rash with red, swollen areas and dark-red centers. Bites may appear in a line or group, usually on areas of the body not covered by clothing, such as the hands, neck or feet. There may be very itchy blisters or hives at the bite site.
  • Spider bites: Most spiders don’t pose a threat to humans and their bites are harmless or mildly irritating, similar to a bee sting. Dangerous spiders include the brown recluse spider or black widow. A single raised papule, pustule or wheal may appear at the site of the bite followed by redness and tenderness. The bite will appear as two small puncture marks. Severe allergic reactions to a spider bite may require medical attention.
  • Scabies: Symptoms may take 4-6 weeks to appear and may include an extremely itchy rash that is pimply, made up of tiny blisters or scaly. They may cause raised, white or flesh-toned lines.
  • Tick bites: Tick bites can cause pain or swelling at the bite site. They may also lead to a rash, burning sensation, blisters or difficulty breathing. The tick often remains attached to the skin for a long time.

Why do insects bite?

Most insects do not usually attack humans unless they are provoked and trying to defend themselves. For example, some insects may sting to protect their hives or nests or when disturbed.

Some insects, however, bite because they must as part of their life cycle. For example, only female mosquitoes bite. This is because they require the protein in the blood to produce eggs.

Are bug bites dangerous?

Most bug bites aren’t dangerous and mild symptoms that resolve on their own. For example, bites from fleas, mites and mosquitoes tend to cause itching rather than pain.

But some insect bites can cause significant discomfort or serious reactions, especially if the insect injects venom that contains proteins or other substances that trigger an allergic reaction. Bites or stings from bees, wasps, hornets, yellow jackets and fire ants (members of the Hymenoptera family) may cause serious allergic reactions that can even be life-threatening and require immediate medical attention.


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Medically Reviewed on 6/2/2021
Powers J, McDowell RH. Insect Bites. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021.

Medline Plus. Insect Bites and Stings.