Louse (Head louse or Body louse)
Scientific Name: Pediculus humanus
Order & Family: Order: Psocodea (formerly Phthiraptera), Family: Pediculidae
Size: 2.0 mm to 3.0 mm (roughly the size of a sesame seed).
Natural Habitat
Found exclusively on humans, either on the scalp and hair (head lice) or on clothing and bedding (body lice).
Diet & Feeding
Obligate hematophages; they feed exclusively on human blood several times a day.
Behavior Patterns
They are wingless and cannot jump or fly; they move by crawling. They attach their eggs (nits) to hair shafts or clothing fibers and have a life cycle consisting of egg, nymph, and adult stages.
Risks & Benefits
Risks include intense itching, allergic reactions to bites, and secondary skin infections from scratching. Body lice specifically can transmit diseases like epidemic typhus and trench fever. There are no ecological benefits to humans.
Identified on: 4/26/2026