Female mosquitoes find blood—which they need in order to reproduce—in part by using smell receptors on their antennae and mouths. These receptors respond to chemical signals emanating from a host’s body (host = you). Humans give off several hundred such chemicals, and each of us has a unique blend, a chemical signature. The unlucky among us have more of the ingredients that skeeters love, so we get bitten more often.

READ MORE: The Science of (Insect) Attraction