Head louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea; Family: Pediculidae

Size: 2 to 3 mm in length (roughly the size of a sesame seed)

Exclusively on the human scalp, clinging to hair shafts and skin

Obligate hematophages; they feed exclusively on human blood several times a day

Wingless and incapable of hopping or flying; they move by crawling. They lay eggs (nits) firmly glued to the base of hair shafts near the scalp

Causes intense itching and scalp irritation. They are not known to transmit diseases, but scratching can lead to secondary bacterial skin infections

Identified on: 6/18/2026