Lice eggs, also known as nits, are tiny yellow, brown or tan dots that lie on hair shafts close to the scalp. They cannot be removed by regular brushing or shaking of the head. Lice eggs hatch within one to two weeks after being laid.
Head lice are tiny insects that live in human hair and feed on small amounts of blood drawn from the scalp. Lice are contagious and hard to get rid of. Adult lice are grayish-white or tan and about the size of a sesame seed. They become adults one to two weeks after hatching. Lice may be seen by parting the hair into small sections and using a fine-tooth comb on the scalp.