Head Lice Life Cycle


Lice eggs are called Nits. The female louse will lay eggs on any fibrous material or hair. The eggs are oval shaped, yellowish white in color and attached with a cement type glue to the hair shaft and are often mistaken for dandruff. An egg is laid at the base of the hair. They are usually near the scalp, about ¼” to ½” away. Eggs take 6 to 7 days to hatch.


Once the egg is hatched, the nymph which are clear in color start to feed on human blood almost immediately turning their color to a reddish brown. It takes 7 to 10 days for a nymph to develop into a full adult louse. Nymphs do not mate or lay eggs and are small in size.


A louse is an adult that can live up to 30 days on a human head and lay over 100 eggs in her lifetime, approximately up to 10 eggs per day. A full grown louse is about the size of a sesame seed. They are usually grayish brown in color.

There are three stages in the life of a louse: the egg or nit, the nymph and the adult louse