Human Head Louse (Egg/Nit)
Scientific Name: Pediculus humanus capitis
Order & Family: Order: Psocodea (formerly Phthiraptera), Family: Pediculidae
Size: Nits (eggs) are approximately 0.8 mm long; adults are 2-3 mm long.
Natural Habitat
Exclusively on the human scalp and hair shafts; they cannot survive more than 24-48 hours away from a human host.
Diet & Feeding
Obligate ectoparasites that feed exclusively on human blood several times a day.
Behavior Patterns
Nits are cemented to the hair shaft near the scalp. They cannot hop or fly and spread through direct head-to-head contact or sharing personal items like combs or hats.
Risks & Benefits
Causes intense itching and secondary skin infections from scratching. They are a significant social nuisance but do not transmit infectious diseases like body lice do.
Identified on: 3/1/2026