Where do lice and nits appear on the head? - briefly
Lice typically inhabit the scalp, concentrating around the hairline, behind the ears, and at the nape of the neck. Nits are cemented to the base of hair shafts, most often within a centimetre of the scalp surface.
Where do lice and nits appear on the head? - in detail
Head lice (Pediculus humanus capitis) and their eggs, commonly called nits, occupy distinct zones on the human head. Adult insects cling to the hair shaft close to the scalp, where temperature and blood supply support feeding. Nits are cemented to the hair shaft by a sticky secretion, typically within 1 cm of the scalp surface; this proximity ensures optimal hatching conditions.
The majority of infestations concentrate on the following regions:
- Scalp skin behind the ears – warm, moist environment promotes survival.
- Upper occipital area – hair density provides shelter and easy access to blood vessels.
- Crown and vertex – central location allows rapid movement across the head.
- Neck margin – hair extending onto the neck offers additional habitat.
Less common sites include:
- Eyebrow and eyelash hair – occasional colonization, especially in children.
- Facial hair (beard, moustache) – rare, usually associated with secondary spread.
- Body hair (chest, arms) – atypical, indicates extensive infestation.
Nits remain attached to the hair shaft until hatching, after which nymphs emerge and migrate to the scalp surface. The cemented eggs are most resistant to removal when located near the scalp, where the hair is thickest and the skin is most vascularized. Regular inspection of these areas enables early detection and effective treatment.