Head lice are tiny, wingless insects that feed on human blood. They are spread through head-to-head contact or by sharing personal items, such as hats, combs, or brushes. Nits are the eggs of head lice. They are small, oval-shaped, and white or yellow in color. Nits are typically attached to the base of hair shafts, close to the scalp.
Head lice and nits can be a nuisance, but they are not dangerous. However, they can cause itching, redness, and irritation of the scalp. In some cases, head lice can also lead to a bacterial infection of the scalp.