The body louse. Phthirus pubis - The pubic louse. Lice are insects than live on rather than in the body. They are wingless and have six legs on which are attached strong claws, which they use to grasp on tightly to hair shafts or clothing fibres. Head lice, the most common infestation in humans, are colloquially known as cooties and their eggs are called nits .
Pubic lice are smaller than the other two species, and have a short body resembling a crab.
Hence the name crabs . Steven Lamb MBChB Department of Dermatology, Health Waikato.