Louse

Typically found on a host organism (human or animal hair/clothing) or in nesting/sleeping areas.

Obligate parasites that feed exclusively on the blood of their host.

They are wingless, crawling insects that move between hosts via direct contact or shared items like brushes, hats, or bedding. They lay eggs (nits) that glue to hair shafts or clothing fibers.

Risks include intense itching, skin irritation, and secondary bacterial infections from scratching. Some species can transmit diseases like epidemic typhus. There are no ecological benefits to humans.