Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea (formerly Phthiraptera); Family: Pediculidae

Size: Adults are approximately 2-3 mm long; about the size of a sesame seed.

Head Louse

Natural Habitat

The human scalp, where it lives and deposits eggs (nits) onto hair shafts close to the scalp surface.

Diet & Feeding

Strictly hematophagous; they feed on human blood several times a day to survive.

Behavior Patterns

They are wingless and cannot jump or fly; they move by crawling from hair to hair. They have a lifecycle consisting of three stages: egg, nymph, and adult.

Risks & Benefits

They cause intense itching (pediculosis) and secondary skin infections from scratching; however, unlike body lice, they are not known to spread diseases. They provide no known ecosystem benefits.

Identified on: 12/27/2025