How do lice appear on a comb? - briefly
When a comb is moved through hair that contains lice, the insects and their eggs grip the teeth and remain on the comb after it is withdrawn. The same transfer can happen if the comb contacts a contaminated surface, allowing nits or lice to adhere directly.
How do lice appear on a comb? - in detail
Lice become visible on a comb when a head‑to‑tooth or fine‑toothed device is run through infested hair, capturing both adult insects and their eggs. The process involves several steps:
- Movement of hair strands: As the comb slides, each hair is separated, exposing the surface of the scalp where adult lice cling with their claws.
- Attachment of insects: Adult lice, typically 2–4 mm long, cling to the hair shaft or scalp. When the teeth of the comb encounter them, the insects are dislodged and trapped in the gaps between the teeth.
- Retention of nits: Female lice embed eggs (nits) 0.8 mm from the scalp. The comb’s narrow spacing can pull these cemented eggs loose, especially if the comb is pressed firmly against the hair.
- Visualization: The captured lice and nits remain lodged in the comb’s teeth, allowing direct observation. Adults appear as small, translucent, brownish bodies; nits appear as oval, white or yellowish shells attached to the hair shaft.
Factors influencing detection include the comb’s tooth density (typically 0.2 mm spacing for nit combs), the thoroughness of the pass (multiple strokes from scalp to ends and back), and the hair’s condition (wet or dry). Repeated combing over several days increases the likelihood of finding all life stages because newly hatched nymphs may emerge after the initial pass.
Effective monitoring therefore requires:
- Use of a fine‑toothed nit comb with 0.2 mm spacing.
- Systematic combing from scalp outward, repeating the motion three to five times per session.
- Inspection of each tooth after every pass, removing captured insects with tweezers or rinsing the comb in hot water.
- Daily repetition for at least one week to capture successive hatchings.
By following these steps, the presence of lice and their eggs becomes apparent on the comb, providing a reliable method for diagnosis and treatment monitoring.