Head louse
Scientific Name: Pediculus humanus capitis
Order & Family: Order: Psocodea, Family: Pediculidae
Size: 2mm to 3mm in length (approximately the size of a sesame seed).
Natural Habitat
The scalp and hair of humans; they are obligate ectoparasites.
Diet & Feeding
Exclusively human blood, which they feed on several times a day.
Behavior Patterns
They do not fly or jump; they move by crawling from hair to hair. Females lay eggs (nits) and glue them to the hair shaft near the scalp for warmth. They cannot survive for more than 24-48 hours off a human host.
Risks & Benefits
Risks include intense itching (pruritus) due to an allergic reaction to their saliva, and potential secondary skin infections from scratching. They are not known to spread disease. There are no ecological benefits to humans.
Identified on: 4/28/2026