Although there are many types of lice, the head louse (Pediculus humanus capitis), is a parasitic insect that can be found on the head and, not so often, the eyebrows and eyelashes of people. Head lice (the plural form of louse) feed on human blood several times a day and live close to the scalp to maintain their body temperature.

There are three stages of Head Lice:

1. egg , also called nit (will hatch after 7-10days)
2. nymph (will go through 3 cycles before turning into an adult
3. adult louse (learn how big lice are in their various stages)

Head Lice have six claws that allow them to crawl around from one hair strand to another hair strand. This is how they move from head to head, which is the main way that causes an infestation to spread between one person to another.

When a female adult louse makes its way to a new head and lays eggs, a new infestation occurs.  When the eggs hatch, the lice will most likely stay on that head throughout the entire lice life cycle. If the head is not treated (see pediculosis treatment) and all lice and eggs are removed, the lice infestation will continue for however long the lice can live.(30-days)