Pediculus or lice, come in three varieties. The first is Pediculus humanis capitis, also known as the head louse and the second is Pediculus humanis corporis, more commmonly known as the body louse. The third type of louse is Phthirus pubis, also known as "crabs." Head, body and pubic lice have a tendency to emerge in crowded areas with low levels of personal hygiene