Lice Health Center
Head lice are tiny parasites that infest hair and feed on blood from the scalp. While an infestation of these parasites are known as lice, a single one is called a louse. Itching caused by lice occurs as they attempt to get to the blood in the scalp.
Lice also lay eggs called nits, in the hair, which are very difficult to get rid of. Head lice mainly affect children and spread quickly and easily from child to child. However, lice have also been known to infest the household members of the infested children as well.
Contrary to popular belief, head lice have nothing to do with poor hygiene and are very common in the U.S. When researchers tested large groups of children to see how many have lice, they found that close to 10% do. There is no proof that lice prefer clean or dirty hair. They feed on blood, not dirt or skin cells on the scalp. Whether or not lice prefer long hair over short hair is still unclear.