Lice are parasitic insects that infest hair, feeding on human blood. Although there can be a stigma associated with lice, an infestation does not indicate poor hygiene. These small (1/8 inch), wingless insects generally spread by head-to-head contact or sharing hats or hairbrushes. Adult lice have a lifespan of about 30 days on a person, but they will only live for a day or two on other surfaces. They cannot be transmitted by pets.

Head lice have three phases of development: the egg (or “nit”), nymph and adult. On infested people, all stages are found on the scalp or very near it, especially behind the ears and near the neckline. Adults and nymphs cling tightly to the hair shaft with hook-like claws at the end of their legs. Nits attach themselves firmly near the scalp and are very difficult to remove. To prevent head lice infestation, avoid sharing clothing, combs, brushes or towels. If you know an infested person has visited your home recently (or if you’re trying to prevent one member of the family from spreading lice to everyone else), machine wash and dry bedding, clothing and other washable fabrics on high heat.