The three main types of lice that infect people are :

 Head lice, Body lice, and Pubic lice (crabs). Each type of lice bites your skin, causing extreme itching. If you scratch the bite, you can break the skin and get other skin infections. Each type of Lice has different symptoms. The most common symptoms are listed below.


Head Lice: [Also called Pediculus humanus capitis (peh-DICK-you-lus HUE-man-us CAP-ih-TUS), head lice are parasitic insects found on the heads of people. Having head lice is very common.]


Itchy scalp. 
Tiny grayish white, football-shaped eggs (about the size of a poppy seed) clinging to hairs close to the scalp.
Grayish or brownish insects one-eighth of an inch long or smaller. Look for them behind the ears or at the nape of the neck.
Sores on the scalp. Caused by scratching, these can become infected.

Body lice (scabies): [Scabies is an infestation of the skin with the microscopic mite Sarcoptes scabei. Infestation is common, found worldwide, and affects people of all races and social classes. Scabies spreads rapidly under crowded conditions where there is frequent skin-to-skin contact between people, such as in hospitals, institutions, child-care facilities, and nursing homes.]


Red, raised bumps caused by bites on the shoulders, buttocks, and elsewhere on the torso.
Eggs (nits) on clothing, most often in the seams of underwear.


Pubic lice (crabs): [called "crabs," pubic lice are parasitic insects found in the genital area of humans. Infection is common and found worldwide.]


Itching in the genital region.
Tiny crablike insects on the skin in the crotch area.
Small dark specks, which are crab feces, on underwear.
Eggs (nits) attached to the base of pubic hair