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)
Natural Habitat
The scalp and hair follicles of human beings
Diet & Feeding
Exclusively human blood, obtained through the scalp several times a day
Behavior Patterns
They are wingless, obligate ectoparasites that cannot jump or fly; they spread primarily through direct head-to-head contact. Females attach eggs (nits) to hair shafts near the scalp.
Risks & Benefits
Causes intense itching and potential secondary skin infections from scratching; however, they are not known to spread disease-causing pathogens. They provide no ecosystem benefits.
Identified on: 4/28/2026