What is the life cycle of head lice and Nits?

Head lice have a life span of about 30 days.

A diagram describing the  life cycle of a head lice is shown here in the Head Lice Life Cycle diagram.

An adult female head louse lays about 6 eggs or nits each day.  Each nit is about the size of a grain of salt and can range from white to brown.

After about 7 to 10 days, the nit eggs hatch and new head lice are released. These head lice are called Nymphs and are about 1/32” (1mm ) in length.

The nymphs take about 14 days to mature into adult head lice and start laying nit eggs.

An adult Head louse is about 1/8” (3mm) in length.

An adult female head louse mates once and then continues to lay eggs each day.  In their 30 day lifetime, adult female head lice lay about 100 nit eggs each.

An unnoticed infestation of head lice can result in hundreds of head lice living on a scalp.

To see a table showing the rapid rise in head lice numbers use the Head Lice  and Nit Population Calculator here.

Hatched nit eggs remain attached to the hair shaft. The hatched nit egg is white and nearly  translucent. It can be seen as a small white blob stuck to a hair.  Since a nit is firmly attached to a hair shaft, it moves away from the scalp as the hair grows.

The term nits is sometimes used to describe the head lice although nits properly refers to the eggs or egg cases.

To understand how to break the head lice life cycle then click here and read this ebook.