Nits found within ¼ of an inch from the scalp often mean the nits are alive and treatment is required. If the nits are greater than ¼ of an inch from the scalp, you must ask your doctor if therapy is necessary. Head lice are mostly spread by direct head-to-head contact with hair of other people who have head lice. Head lice are much less generally spread by way of contact with an infested person’s...