Infestation of the scalp with a species of blood- sucking louse, the head louse Pediculus humanus capitis. The condition is known medically as pediculosis & consists of severe itching, which may lead to bacterial infection. If untreated, the hairs may become matted together by the exudate from weeping skin lesions. The photograph shows the strands of hair covered in eggs, commonly known as nits", which are glued in place by a cement-like mixture secreted by the adult. One adult louse is visible in the lower left corner of the photograph. The lice are eliminated using gamma benzene hexachloride shampoo."