There are three immature nymphal stages separated by molts. Their appearance and habits are not greatly different from those of adults. Both nymphs and adults have piercing-sucking mouthparts, which pierce the skin for a blood meal. Adults may survive 3 to 5 days without a blood meal. Normally a young louse will mature to an adult in 3 to 5 weeks.
Lice pass through a three-stage life cycle, including three stages as immature nymphs.
Crab lice are found primarily in the hair of the pubic area. They may also be found in the hair of the armpits and chest, in the beard or mustache and even rarely on the eyebrows and eyelashes. Their life cycle resembles that of the head and body louse except that their development from egg to adult normally requires from 4 to 6 weeks. Eggs hatch after about 6 to 8 days into nymphs that molt three times before becoming adults. Adult crab lice live about 30 days while on the host.