Louse

Scientific Name: Phthiraptera (Order)

Order & Family: Order: Phthiraptera; Families include Pediculidae (human head/body lice) and Pthiridae (crab lice)

Size: 1 to 3 mm in length (roughly the size of a sesame seed).

Louse

Natural Habitat

Exclusively on the bodies of warm-blooded hosts, specifically humans for the Pediculus species, residing in hair or clothing fibers.

Diet & Feeding

Obligate parasites that feed exclusively on host blood multiple times a day.

Behavior Patterns

Wingless insects that move by crawling; they cannot jump or fly. They attach their eggs (nits) firmly to hair shafts or clothing seams and have a life cycle consisting of egg, nymph, and adult stages.

Risks & Benefits

Risks include intense itching (pruritus) due to allergic reactions to saliva, secondary skin infections from scratching, and in some cases (body lice), the transmission of diseases like typhus. They provide no known ecological benefits to humans.

Identified on: 1/4/2026