虱是昆虫纲中的节肢动物，它生存于宿主的毛发中，并以宿主的血为食。左边是头虱，右边是耻阴虱。
虱:大体 放大
Lice are arthropods of the class Insecta which generally inhabit hair and bite the human host for a blood meal. At the left is the head louse (Pediculus humanis capitis) and at the right is the crab (pubic) louse (Phthirus pubis).
