Head Louse (Nit/Egg)
Scientific Name: Pediculus humanus capitis
Order & Family: Order: Psocodea, Family: Pediculidae
Size: Nits (eggs) are 0.8 mm by 0.3 mm; adults are approximately 2–3 mm long.
Natural Habitat
The scalp and hair of humans, particularly behind the ears and near the neckline.
Diet & Feeding
Obligate ectoparasites that feed exclusively on human blood several times a day.
Behavior Patterns
Nits are firmly glued to hair shafts and cannot be easily flicked off. They hatch in about 8-9 days. Adults avoid light and crawl quickly through hair.
Risks & Benefits
Cause intense itching (pruritus) due to allergic reactions to saliva. While they do not spread disease, secondary infections can occur from scratching. They provide no ecosystem benefits.
Identified on: 4/28/2026