If you are checking your child's head for lice here is what to look for. Lice come in three stages - egg, nymph, and adult louse. The lice eggs or nits are oval in shape and yellowish white in color. They usually appear 1/4 inch away from the scalp and are about the size of the period at the end of this sentence. The nymph looks like a regular louse but is just smaller in size. The adult louse is the size of a sesame seed, has six legs, and is tan to grayish-white in color.