How do you recognize head lice and nits?

Head lice are small, wingless insects that can be seen crawling on the scalp and hair, typically around the nape of the neck and behind the ears. They are about the size of a sesame seed and can be grayish-white or tan. Nits, or lice eggs, are tiny, oval, and usually yellow or white, firmly attached to hair strands close to the scalp. A key sign of infestation is intense itching, caused by an allergic reaction to lice bites.