What do head lice look like?

  • Egg/Nit: Nits are lice eggs laid by the adult female head louse at the base of the hair shaft nearest the scalp. Nits are firmly attached to the hair shaft and are oval-shaped and very small (about the size of a knot in thread) and hard to see. Nits often appear yellow or white although live nits sometimes appear to be the same color as the hair of the infested person. Nits are often confused with dandruff, hair debris, or hairspray droplets. Head lice nits usually take about 8-10 days to hatch. Eggs that are likely to hatch are usually located no more than ΒΌ inch (or 1 centimeter) from the base of the hair shaft.
  • Nymph: A nymph is an immature louse that hatches from the nit. A nymph looks like an adult head louse, but is smaller. To live, a nymph must feed on blood. Nymphs mature into adults about 9-12 days after hatching from the nit.
  • Adult: The fully grown and developed adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. Adult head lice may look darker in persons with dark hair than in persons with light hair. To survive, adult head lice must feed on blood. The adult head louse life span is about 30 days on a person's head but the louse will die within one or two days if it falls off a person. Adult female head lice are usually larger than males and can lay about six eggs each day.