Most people had head lice as a kid, but fewer will admit to a pubic lice infestation. The crab louse is a harmless critter, but can cause irritation if it sets up home in your groin. Having a shave or wax down there is a lot less obvious than getting a buzz cut up top, so getting rid of these annoying ectoparasites is usually easy. Yet keeping downstairs hairless is increasingly popular in general, which is bad news for little Pthirus pubis seeking to spread. Ever since Carrie Bradshaw and pals made going bald popular, crab lice have been seen less and less.