Stock Photo: CRAB LOUSE. CRAB LOUSE The crab louse is a tiny wingless insect that lives on blood. This flat insect has strong pinchers which attach to the pubic hairs. It is transmitted by sexual contact. The crab louse can also be harbored on hairs in the perianal region, the armpits, and the beard. Female lice lay clear eggs which hatch in about 8 days.