Light micrograph of the pubic louse, Phthirus pubis, also known as the crab louse. An infestation of P. pubis causes pediculosis, the symptoms of which are severe itching and a rash. The lice suck blood, feeding 5 times a day. They spread through sexual contact and via bedding or clothing. Each of the louse's 6 legs terminates in a massive claw, which folds inward to meet a thumb-like projection on the opposite side. The louse climbs and swings through its hairy habitat, locking into position when it is disturbed, for instance by scratching or washing. Magnification: x22 at 6x4.5cm size, x14 at 35mm size.