Adult male, female louse and nit.

adult louse clear

Adult lice are clear in color before they feed.


The nit, or egg, attached to hair shaft.

nit shell

An empty nit shell attached to hair shaft.

double nit hatching

Double nit hatching.

Adult male louse

Adult male louse.

Head Lice Picture

Stages of a louse: nit, nymph, and adult.

Head Lice w Ruler

Lice are a fraction of a centimeter in size.


It is estimated that head lice infestation affects about 12 million children a year. These tiny insects do not discriminate and will be happy on any human host. Head lice will climb on to your hair if it's dirty or clean, although it is said that they prefer clean heads.

Head lice do not fly or jump, but can move very quickly around the head or from hair strand to hair strand. Lice survive by feeding on human blood and cannot live off a human host for more than about 36 hours.

Lice life cycle facts:

  • The life cycle of head lice lasts about 30-35 days from egg (or nit) to adult.
  • The female louse can lay as many as 10 eggs per day.
  • The incubation of the egg usually lasts between 7-10 days.
  • After a nit hatches, the second stage of life, or the nymph stage, also takes about 7-10 days.

The nymph typically molts 3 times before reaching its adult form.