MODEL RELEASED. Head lice. Six-year-old boy with head lice scratches at his head. Head lice are small wingless insects that live on and suck blood from the scalp. They cause intense itching leading to scratching and skin inflammation. Hair washing with lotions or shampoos containing malathion or carbaryl kills the lice rapidly. Dead lice and nits (eggs) are then removed using a fine-toothed comb. Head lice are spread by direct contact. They occur most commonly in children.