Louse

Found exclusively on the human scalp and hair, most commonly behind the ears and at the nape of the neck.

Obligate parasites that feed solely on human blood, typically several times a day.

They do not fly or jump but crawl from person to person through direct head-to-head contact. They attach eggs (nits) firmly to the base of hair shafts.

They cause intense itching and scalp irritation from allergic reactions to their saliva. While they are not known to transmit disease, heavy scratching can lead to secondary bacterial skin infections.