How Big Can Head Lice Grow?

Head lice can be quite a nuisance, but they aren’t as hard to remove as you think. The louse, a parasitic insect in the order Psocodea, has three life stages: egg, nymph, and adult. The first stage of the life cycle is the egg, which is laid by the female louse. The nymph is about the size of a pinhead and has a yellow nit shell. The nymph will go through three molts before reaching maturity. After this, the louse will die, which is why you should treat lice quickly.

Full-grown head lice measure about two to three millimeters long, with six legs. They can stick to human hair and crawl along it. The larvae are much smaller and can be spotted with the help of a magnifying glass. Once the nymphs have completed the life cycle, the head lice will be about two to three millimeters long. They will stick to the hair at a distance of less than a centimeter.

Before hatching, lice eggs look like tiny dots. The lice then lay their nits on the hair shaft close to the scalp. The warmth of the hair shafts keeps the nits safe and warm. Lice nits look like dandruff and are not easily removed by brushing or shaking.