Head Lice Facts

What are Head Lice?

Lice is the plural term that refers to more than one louse. Head lice are tiny insects that live on the scalp, usually on children 10 and under. They do not live on pets or other animals. Head lice have six legs, each with a curved claw that can tightly grasp the scalp hair. Head lice crawl easily between hairs, but they cannot fly or jump.

Head lice only feed on human blood, drawing a tiny drop with each meal. The louse does not dig or burrow into the skin - it uses its needle-like mouthparts to find a blood vessel in the skin.

Not all insects on the hair are head lice. It is important to make sure that you really have a living (crawling) louse before treating. If you are unsure, consult with a medical professional for help and more head lice information.

How Do You Get Lice?

Head lice are almost always caught directly from another person. Usually, this happens when children are in direct head-to-head contact, such as sharing a bed, or playing together in close contact.

Louse eggs (nits) cannot move and are not transmissible. Head lice are rarely transferred or transmitted on a shared comb, brush, hat, headphone, helmet, jacket, coat hook or in cubbies or storage lockers.

Head lice that fall off a person quickly starve and usually die within a few hours. So lice that fall on a desk, floor or coat at school will not be alive the next day. Clothing, stuffed animals, theater seats and other items are not threats to spread head lice. Bathing every day will not prevent or wash away head lice. Cleaning the home or bagging toys and clothing won’t help you prevent or get rid of head lice.

Head Lice Life Cycle

Head lice only live for about three weeks. An adult female louse will lay about six eggs (nits) each day. She attaches each egg with a cement-like material that does not wash out. If the louse mated, her eggs may develop during the next 9 days. The eggs do not grow, move or cause any health problems. Once developed, the young louse (called a nymph) breaks out of the egg, crawls on the hair and leaves behind the now empty eggshell. The empty egg will never produce another louse, but it will remain glued to the hair until it is broken or cut off.

The nymph will grow in size and shed its skin every few days until it has matured to become an adult. Only the adult female can lay eggs.