What do lice and their nits look like? - briefly
Adult head lice are about 2–4 mm long, gray‑white, with a flattened body and six legs ending in clawed tarsi that cling to hair shafts. Their eggs, or nits, appear as tiny oval shells 0.8 mm in size, firmly glued to the base of each hair and often visible as whitish or yellowish specks that may darken after hatching.
What do lice and their nits look like? - in detail
Lice are small, wing‑less insects that measure approximately 2–4 mm in length. Their bodies are flattened laterally, which allows them to move easily through hair shafts. The head is broader than the thorax, and the abdomen tapers toward the rear. Color varies from pale gray to brown, often matching the host’s hair or skin tone, which aids concealment. Six legs end in claw‑like tarsi equipped with tiny hooks that grip individual strands of hair. Antennae are short and concealed beneath the head capsule.
Nits, the eggs of lice, are oval and about 0.8 mm long. Their shells are rigid, translucent to white, and become darker as the embryo develops. Nits are firmly cemented to the hair shaft about 1–2 mm from the scalp, using a proteinaceous adhesive that resists removal. The attachment point appears as a tiny, dome‑shaped protrusion; the egg itself is smooth, with a slightly pointed operculum at one end through which the nymph emerges.
Key visual differences between live lice and nits:
- Mobility: Lice move actively; nits remain stationary.
- Shape: Lice have a distinct body segmentation; nits are smooth ovals.
- Color: Lice range from gray to brown; nits start clear and darken over time.
- Location: Lice are found crawling on the scalp or body hair; nits are fixed near the scalp, often at the base of hair strands.
Head lice (Pediculus humanus capitis) and body lice (Pediculus humanus corporis) share the same general morphology, but body lice are slightly larger (up to 4 mm) and tend to lay nits on clothing fibers rather than hair. Both species’ nits exhibit the same attachment method and developmental timeline: incubation lasts about 7–10 days before hatching, after which the nymph matures in another 7–10 days.
Recognizing these characteristics enables accurate identification and effective treatment. Visual inspection should focus on the scalp’s hair base for cemented nits and on the hair shafts for active insects, noting the described size, shape, color, and placement patterns.