A lice infestation is diagnosed by looking closely through pubic
hair for nits, nymphs, or adults. It may be difficult to find
nymph or adult; here are usually few of them and they can move
quickly away from light. If crawling lice are not seen, finding
nits confirms that a person is infested and should be treated.
If you are unsure about infestation or if treatment is not successful,
see a health care provider for a diagnosis.