Head lice are acquired by direct contact with an infested person's hair. Only rarely would lice be transferred by shared combs, brushes, hats or other hair accessories.
It is not necessary to isolate infested people or keep children with head lice home from school. Head lice neither are caused by, nor a sign of, poor hygiene or housekeeping.
Head lice sometimes go away on their own because there are not enough insects to maintain the infestation, or they may persist for an indefinite period without treatment. With proper treatment, the infestation usually goes away within about two weeks.