Adult lice are the mature stage of the lice life cycle and are stages of lice for reproducing and spreading infestations. They are small, wingless insects, approximately 2-3 mm long (about the size of a sesame seed). Adult lice have six legs, each ending in claws that are perfectly adapted for grasping onto human hair strands. This structure allows them to move quickly and cling tightly to the scalp, making it difficult to remove them.
Adult lice have a flat, oval-shaped body that is usually grayish-white or tan, though their color may appear darker after feeding on blood. As parasites, they rely on human blood for survival, feeding multiple times a day through specialized mouthparts. Adult lice are typically found close to the scalp, especially around the neck and behind the ears, where warmth and blood supply are most accessible.
One key characteristic of adult lice is their high reproductive rate. Female lice can lay between 6 to 10 eggs (nits) per day, and once they begin laying, they continue daily until the end of their lifespan. Without treatment, a single adult louse can produce hundreds of eggs, resulting in rapid infestation if left unchecked.