Head lice infestation (also known as pediculosis capitis,[1] nits,[2] or cooties[3]) is the infection of the head hair and scalp by the head louse (Pediculus humanus capitis).[4] Itching from lice bites is common.[5] During a person's first infection, the itch may not develop for up to six weeks.[5] If a person is infected again, symptoms may begin much more quickly.[5] The itch may cause problems with sleeping.[6] Generally, however, it is not a serious condition.[7] While head lice appear to spread some other diseases in Africa, they do not appear to do so in Europe or North America.[4][6]