How do I know if someone has lice?
The first sign is usually an itchy head: the skin reacts to the louse bites and makes people scratch. People with lice might also feel a tickling sensation of something moving in their hair, close to the scalp, especially at night. You can also spot eggs attached to the hair strands, immature lice in nymph form, or fully-grown lice. (Gross, we know.)