Answer 5 quick questions. Our diagnostic engine cross-references your bite's appearance, location, timing, sensation, and environment against 13 common biting pests to identify the most likely culprit — with first aid and a treatment plan.
Takes about 60 seconds. No account needed.
Most "what bit me" guides online give you a flat list of bites and tell you to visually match yours. The problem is that many bites look nearly identical — a bed bug bite, a flea bite, and a mosquito bite can all present as small red itchy welts. Visual matching alone is unreliable.
This diagnostic takes a different approach. Instead of relying on a single factor, it cross-references five independent data points — what the bite looks like, where it is on your body, when you noticed it, what it feels like, and details about your environment — then runs a weighted scoring algorithm against 13 of the most common biting and stinging pests in North America. Each combination of answers adjusts the probability score for every pest simultaneously, and the results show you a ranked list with confidence levels.
This is the same multi-factor approach a trained pest control operator uses in the field. A cluster of bites on exposed arms found in the morning strongly suggests bed bugs. That same cluster on ankles after being in the yard points to fire ants. The bite appearance might be identical, but the supporting context changes the diagnosis entirely.
Most insect bites and stings are medically minor and resolve on their own within a few days with basic first aid — wash with soap and water, apply a cold compress, and use over-the-counter antihistamines or hydrocortisone cream for itching. However, certain situations require prompt medical attention.
Seek emergency care immediately if you experience difficulty breathing, throat tightening, widespread hives or swelling beyond the bite site, dizziness, or a rapid pulse after any sting or bite — these are signs of anaphylaxis, a life-threatening allergic reaction that requires epinephrine. An expanding bullseye rash around a bite suggests possible Lyme disease from a tick and warrants a doctor visit for doxycycline treatment within 72 hours. A bite that develops a central blister with expanding tissue damage may indicate a brown recluse bite and needs medical evaluation. Any bite that becomes increasingly red, warm, swollen, or painful after 48 hours may be developing a secondary bacterial infection and should be seen by a healthcare provider.
For complete visual identification guides, bite comparison charts, and detailed first aid protocols for every biting and stinging pest, visit our full bite identification reference guide. You can also use our AI photo identification tool to upload a picture of the bite or the pest itself for instant species matching, or browse the complete pest library for in-depth profiles on any of the 300+ species we cover.