Lice nits are tiny, teardrop-shaped eggs about the size of a knot in thread, measuring roughly 0.8 mm long and 0.3 mm wide. They range from yellow to white in color and attach firmly to individual hair strands close to the scalp. If you’re checking a head right now, here’s exactly what to look for and how to tell nits apart from dandruff or other debris.
Shape, Color, and Size
Nits have a distinct teardrop or oval shape, which is one of the easiest ways to identify them. When they contain a live embryo, they tend to be yellowish-brown or tan. After the egg hatches or dies, the empty casing shifts to white, translucent, or grayish. Both versions can be visible to the naked eye, but just barely. At less than a millimeter long, they’re smaller than a sesame seed and closer in size to a grain of sand.
You’ll typically spot them on individual hair strands rather than sitting on the scalp itself. Each nit encases a single egg inside a hardened sheath that wraps around the hair shaft. Female lice secrete a glue-like substance from a specialized gland as they lay each egg, and this substance hardens into a protective shell that cements the nit firmly in place. This glue is protein-based and remarkably strong, which is why nits don’t slide or flake off when you touch them.
Where to Look on the Head
Nits are laid right at the base of the hair shaft, usually within about a quarter inch of the scalp. The warmth near the skin is necessary for incubation, so fresh nits cluster close. The most common spots are behind the ears and along the back of the neck, though they can appear anywhere on the head.
The distance from the scalp also tells you something important. Nits found within a quarter inch of the scalp may be viable and part of an active infestation. Nits found farther out on the hair shaft, more than a quarter inch from the scalp, are almost always already hatched or dead. Since hair grows over time, those nits have simply been carried away from where they were originally laid. If the only nits you find are far from the scalp with no crawling lice or close-in nits visible, the infestation is likely old and no longer active.
How Nits Differ From Dandruff
This is the most common source of confusion. Both nits and dandruff can appear as small white or yellowish specks near the scalp, but they behave very differently when you try to move them.
- Attachment: Nits are glued to the hair strand and will not come off with normal brushing, shaking, or blowing. You need to physically slide them along the shaft with your fingernails or a fine-toothed comb. Dandruff flakes fall off easily when touched or brushed.
- Location: Nits attach to hair strands. Dandruff originates from the scalp itself and sits loosely on the skin or hair surface.
- Shape: Nits are uniformly teardrop-shaped and tiny. Dandruff flakes are irregular, often larger, and can look greasy or waxy.
- Feel: Running your fingers along a strand with a nit, you’ll feel a small bump that resists sliding. Dandruff crumbles or brushes away with no resistance.
Other look-alikes include hair product residue (like dried hairspray droplets) and DEC plugs, which are small white cylinders of dead skin cells that form around the hair shaft. These also slide off more easily than nits, which is always the key test. If it moves freely, it’s not a nit.
Live Nits vs. Empty Casings
Telling the difference between a nit that still contains an embryo and an empty shell matters because it determines whether you’re dealing with an active problem. A live, unhatched nit sits close to the scalp and has a darker, more opaque appearance, often yellowish-brown or tan. It may look slightly plump.
After hatching, which takes about 8 to 9 days, the empty casing stays glued to the hair but becomes more translucent, white, or grayish. It may also appear slightly flattened or collapsed compared to a full egg. These empty shells can linger on the hair for weeks or even months after the lice are gone, which is why finding nits alone doesn’t always mean you have an active infestation. The combination of nit color, distance from the scalp, and whether you also spot live crawling lice gives you the full picture.
How to Check Effectively
Good lighting makes a significant difference. Natural daylight or a bright lamp aimed at the scalp will make nits easier to spot. Part the hair in small sections, working your way across the entire head, and pay special attention to the areas behind the ears and at the nape of the neck.
A fine-toothed lice comb (sometimes called a nit comb) is more reliable than a visual check alone. Comb through small sections of damp hair from the scalp outward, then wipe the comb on a white paper towel or cloth after each pass. Against a white background, nits and lice are much easier to see. Nits will appear as small oval dots stuck to the hair strands, while live lice are slightly larger, flat-bodied insects that move quickly.
If you find nits within a quarter inch of the scalp, especially more than a few of them, or if you spot any crawling lice, that points to an active infestation worth treating. A handful of white or clear nits far from the scalp with no live lice is typically evidence of a past problem that has already resolved.