Head Louse

Scientific Name: Pediculus humanus capitis

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

Size: 2.0 mm to 3.0 mm (about the size of a sesame seed)

Head Louse

Natural Habitat

Exclusively on the human scalp and hair

Diet & Feeding

Obligate blood feeders, consuming human blood multiple times a day

Behavior Patterns

They do not fly or jump; they spread through direct head-to-head contact. Eggs (nits) are glued to the base of hair shafts. They die within 24-48 hours if removed from the host.

Risks & Benefits

While they do not transmit disease, they cause intense itching, secondary skin infections from scratching, and significant social/psychological distress. They offer no ecological benefits to humans.

Identified on: 12/27/2025