What are head lice?

Head lice are tiny brown insects that are approximately three millimetres long and live on the human scalp. They lay their eggs (nits) at the bottom of hair follicles on the human scalp and they hatch after about a week. Head lice are only spread by hair to hair contact and they are unable to jump or fly.

Having head lice is not a symptom of a particular hair type or style, nor is it a sign of dirty hair. Their transmission is particularly common in young children due to the amount of time they spend playing together and having physical contact in nurseries and schools.