Head lice are common parasitic insects that live on the human scalp, feeding on tiny amounts of blood. Visually identifying these insects is the first step in addressing an infestation. This guide will help you recognize lice at different stages of their life cycle.
Adult Lice
Mature head lice are small, wingless insects, about the size of a sesame seed, measuring 2 to 3 millimeters long. They possess six legs with hook-like claws that allow them to tightly grip hair strands. Adult lice are often tan or grayish-white, appearing darker or reddish after feeding on blood. They move quickly by crawling along hair shafts, but cannot jump or fly.
Nits (Lice Eggs)
Nits are the eggs laid by female lice and are often the most common sign of an infestation. These tiny, oval-shaped structures are about the size of a pinhead. They can appear yellowish, whitish, or clear before hatching, and may look darker if dead or hatched. Nits firmly attach to individual hair shafts with a waterproof, glue-like substance.
They are found very close to the scalp, within a quarter-inch (6 millimeters), where warmth aids incubation. Unlike dandruff or other scalp debris, nits cannot be easily brushed, flicked, or shaken off the hair. Viable nits are translucent and found close to the scalp, while hatched or non-viable nits are often white or dull yellow and located further down the hair shaft as the hair grows.
Nymphs (Young Lice)
Nymphs are immature lice that hatch from nits. They resemble adult lice but are significantly smaller, with newly hatched nymphs about the size of a pinhead. These young lice are lighter in color or more translucent than their adult counterparts, making them harder to spot. Like adults, nymphs crawl and feed on blood from the scalp to grow and mature. Nymphs undergo several molting stages, increasing in size before reaching adulthood.
Where to Find Them and What Else It Could Be
Lice and nits are most commonly found on the scalp, particularly in warmer areas such as behind the ears, near the nape of the neck, and along the crown of the head. To effectively check for them, use good lighting, such as natural sunlight, and a fine-toothed comb to systematically part the hair in small sections, examining the scalp and hair shafts closely.
It is common to confuse nits with other substances found in hair, such as dandruff, flakes of dry skin, hair product residue, or lint. A key differentiator is that nits cannot be easily dislodged, unlike dandruff flakes or product residue which move or brush off with ease. Dandruff tends to be scattered throughout the hair and on the scalp, while nits are specifically attached to individual hair strands.