Head lice occur in three stages: the nit, the nymph, and the adult. Nits are small, oval-shaped, yellowish eggs. Often they are difficult to see and can be confused with dandruff or droplets of hair spray. After one week the nits hatch into nymphs, baby lice. Nymphs look like small adult lice, but are only about the size of a pinhead. They mature after seven to 14 days of feeding on blood. About the size of a sesame seed, the adult louse can be seen with the naked eye. They live about 30 days, securing themselves to individual hairs with claws found at the end of each of their six legs. They can also be found behind the ears and near the neckline at the back of the neck. An adult female louse may deposit more than 100 eggs in her lifetime at a rate of about six eggs each day.