DefinitionHead lice are tiny insects that live on the scalp. They can be spread by close contact with other people.These lice only live in hair and occasionally eyebrows and eyelashes.See also:Body licePubic liceAlternative NamesLice - head; Nits; Pediculosis capitis - head liceCauses, incidence, and risk factorsHead lice infect hair on the head. They are easiest to see on the neck and over the ears. Tiny eggs on the hair look like flakes of dandruff. However, instead of flaking off the scalp, they stay put.Head lice can survive up to 30 days on a human. Their eggs can live for more than 2 weeks.Head lice spread easily. You can get head lice when you come in close contact with a person who has lice, or by touching their clothing or bedding. Head lice are more common in close, overcrowded l