Head Lice Parasites

Head lice are tiny parasites that live on human heads and feed on human blood. These parasites can cause itching, sores, and tickling in the hair. People usually get them from contact with infected head hair or clothing. Pets do not carry head lice. The most common way to contract head lice is through head-to-head contact, such as during play, sports activities, and slumber parties. People can also contract head lice by sleeping in the same bed with infected head hair.

Adult head lice are gray-white and only two to three millimeters long. These parasites have mouth parts for sucking blood and legs for grasping hair. They feed on the hairs on the scalp and the adjacent areas of the face and neck. They can live up to 55 hours without a host before dying or becoming nonviable.

Head lice are spread through head-to-head contact but can also be spread through sharing clothing or personal belongings. While personal hygiene and cleanliness have nothing to do with getting head lice, the likelihood of getting infected by them is low. Moreover, head lice cannot survive for more than two days without human blood.

Head lice are easily detected by moving a fine-tooth comb through the scalp. They are most often found behind the ears and at the back of the head. You can also detect them by looking for nits attached to the hair shafts. If you find nits that are attached within 1/4 inch of the hair shafts, head lice have infested the head.