Head Louse Nit

Scientific Name: Pediculus humanus capitis

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

Size: Approximately 0.8 mm in length (about the size of a knot in thread).

Head Louse Nit

Natural Habitat

Human scalp and hair shafts, particularly behind the ears and at the nape of the neck.

Diet & Feeding

Head lice feed exclusively on human blood; the nit itself is an egg and does not feed.

Behavior Patterns

Nits are glued to hair shafts by a cement-like substance secreted by the female louse. They hatch in about 8-9 days into nymphs, which must feed immediately.

Risks & Benefits

Causes itching and scalp irritation. They are highly contagious through head-to-head contact but do not spread disease. No ecosystem benefits.

Identified on: 1/11/2026