The life cycle of head lice means the period of time between the moment head lice eggs are laid by the female until the moment head lice die. The head lice life cycle lasts about 45 days.
Head lice reproduce very quickly. The male is a tireless lover who can fertilize 18 females in a row without having a rest. The females mate several times during their adult life, which can vary from ten to forty days, usually about 20 days. They lay up to 10 lice eggs or nits daily.
- From Egg To Nymph: One Week
Head lice incubation period lasts about a week (from 6 to 9 days exactly), which means that head lice eggs or nits hatch about a week after eggs have been laid. Head lice eggs hatch to release a nymph. The latter resembles the adult lice, but of course it is smaller, and it measures about 1 millimeter, the size of a pinhead.
- From Nymph To Adult Louse:
The adult stage is reached after approximately 7 days after three successive molts. Thus, from the laying of the egg to the emergence of adults are 17 days, and the adult will live for about 30-40 days.
- Adult Stage: One Month
The lifespan of an adult louse is about 30 days. This means that head lice, once they have reached the adult stage, will live for about one month. They can only survive this long if on a human head. They need to feed on human blood several times a day. They will die within 48 hours off a human head.
Information provided by Centers for Disease Control and Prevention