Head louse (nit)
Scientific Name: Pediculus humanus capitis
Order & Family: Psocodea: Pediculidae
Size: Nits (eggs) are 0.8 mm; adults are 2-3 mm long
Natural Habitat
Human scalp and hair follicles
Diet & Feeding
Obligate ectoparasite; feeds exclusively on human blood several times a day
Behavior Patterns
Nits are glued to the hair shaft near the scalp; adults crawl quickly but cannot jump or fly; life cycle takes about 30 days from egg to death
Risks & Benefits
Causes scalp itching (pediculosis) and secondary skin infections from scratching; not known to transmit diseases; no benefits to humans or ecosystem
Identified on: 2/24/2026