Head lice are tiny, tan to grayish-white insects about 2 to 3 mm long, roughly the size of a sesame seed. They cling close to the scalp and move quickly through hair, making them surprisingly hard to spot even during a careful check. What most people notice first aren’t the bugs themselves but their eggs, called nits, which look like tiny white or yellowish-brown specks glued firmly to individual hair strands near the scalp.
What Adult Lice Look Like
An adult louse has six legs, a flat oval body, and ranges from tan to grayish-white in color. At about the size of a sesame seed, it’s visible to the naked eye but easy to miss because it moves fast and avoids light. Lice don’t fly or jump. They crawl, and they tend to scurry away from a part in the hair or a flashlight, which is why you often catch only a quick glimpse before they disappear.
After feeding on blood from the scalp, a louse can appear darker or more reddish-brown, which sometimes helps you spot it against lighter hair. On very dark hair, the pale body of an unfed louse can be harder to see. Wetting the hair and using a fine-toothed lice comb (with teeth spaced about 0.2 mm apart) slows them down considerably and makes detection much easier than a visual-only search.
What Nits Look Like on the Hair Shaft
Nits are the eggs that female lice cement to individual strands of hair, usually within about a quarter inch of the scalp. They’re oval, extremely small (about the size of a knot in thread), and can be white, yellowish-brown, or almost translucent depending on whether they’ve hatched. Each nit is attached with a glue-like substance the louse secretes, which makes it grip the hair tightly and resist normal washing or brushing.
This firm attachment is actually the most reliable way to tell nits apart from dandruff. Dandruff flakes slide off easily when you flick them or run your fingers along the strand. A nit won’t budge. You’ll need to pinch it between your fingernails and slide it deliberately down the hair to remove it. If you’re unsure what you’re looking at, that simple test gives you a clear answer.
Nit color also tells you something useful. Darker, yellowish-brown nits close to the scalp are more likely to be viable (containing a developing louse). White or clear shells found farther from the scalp, typically more than a quarter inch away, are usually empty casings left behind after hatching, or eggs that never developed. Finding numerous nits within about 6 mm of the scalp strongly suggests an active infestation, while nits only farther out usually indicate a past one.
What Nymphs Look Like
When a nit hatches, the baby louse that emerges is called a nymph. It looks like a miniature version of an adult, about the size of a pinhead. Nymphs are the hardest stage to spot because of their tiny size and nearly translucent coloring. They darken slightly as they feed and grow, reaching full adult size in about seven days after hatching.
If you’re combing through hair and finding nymphs, that confirms an active, reproducing infestation rather than leftover nits from an old one.
Where to Look on the Head
Lice and nits don’t distribute evenly across the scalp. They prefer warm, sheltered spots. The most common areas to check are behind the ears and along the neckline at the back of the head. These zones stay warmer and provide the consistent temperature lice need for their eggs to develop. Start your search there before working through the rest of the hair.
Good lighting helps. Natural daylight or a bright lamp aimed at the scalp makes both nits and live lice easier to see. Sectioning the hair into small parts with clips and examining one area at a time keeps the search systematic, especially in thick or long hair. A magnifying glass can help if you’re struggling to tell nits from hair debris.
Nits vs. Dandruff vs. Hair Product Residue
From a distance, nits, dandruff flakes, and dried hair spray droplets can all look like small white specks in the hair. Up close, they’re quite different.
- Nits are uniform, oval-shaped, and stuck firmly to one side of a hair strand. They don’t brush off.
- Dandruff appears as flat, irregularly shaped flakes of dry skin, white to yellowish, that slide off the hair or scalp easily when touched.
- Hair product residue tends to coat the hair more generally rather than attaching as a distinct speck on one strand. It rinses out with water; nits do not.
If you can easily flick a speck away with your finger, it’s not a nit.
Signs on the Scalp Itself
Beyond spotting the insects or their eggs, there are visible changes on the skin that suggest lice. Persistent scratching from the itch of louse bites can cause small red bumps on the scalp, the back of the neck, and the shoulders. On lighter skin tones these bumps appear red; on darker skin they can be harder to see and may look more like raised patches or feel like small welts under your fingertips.
Repeated scratching can break the skin, and those small wounds sometimes get infected. If you notice crusty or oozing spots on the scalp along with itching, that’s a sign the scratching has gone on for a while and the skin needs attention beyond just lice treatment.
How to Confirm an Active Infestation
The gold standard for confirming lice is finding a live, crawling louse. Finding nits alone, especially farther than a quarter inch from the scalp, doesn’t necessarily mean there’s a current problem. Those may be remnants of an old infestation that’s already resolved.
Wet combing is the most effective detection method. Dampen the hair, apply conditioner to reduce friction, and pull a fine-toothed lice comb slowly from the scalp to the ends of the hair. Wipe the comb on a white paper towel or tissue after each pass. Against the white background, even tiny nymphs become visible. Go through the entire head methodically, section by section. The process takes 15 to 30 minutes depending on hair length and thickness, but it catches cases that a quick visual check would miss.