Lice Eggs, Nits, Nymphs & Adults: FAQ

Lice eggs/nits are laid by adult female lice, often at the base of the hair shaft very close to the scalp. They are oval-shaped and very small (about the size of a knot in a piece of thread), and they are firmly attached to the hair shaft. Nits often look yellow or white, though they can also appear to be the same color as the person’s hair.

Lice eggs take about 8 to 9 days to hatch into an immature louse known as a nymph. These look like adult lice but smaller, and they mature about 9 to 12 days after hatching. When the nymph becomes an adult louse, it is capable of laying eggs.

Yes. In fact, you are more likely to see nits in a child’s hair than to see adult lice crawling around. Lice eggs typically take 1 to 2 weeks to hatch after being laid and, even then, the shell remains firmly attached to the hair shaft. As the child’s hair grows, the empty shell moves further from the scalp, becoming more visible.

Most people become aware of a lice infestation when they start to get itchy or when someone finds nits or live lice in their hair. Children with lice infestations sometimes complain that they feel things moving in their hair, but it is the live lice that cause this sensation — you can’t feel the nits.

In most cases, itching and scratching is caused by a reaction to the saliva of lice when they bite, not the eggs. Depending on the severity of the infestation and the sensitivity of the child’s scalp, it could take several weeks for the itching to develop. In some cases, you may also see small red bumps on the scalp or sores that develop from intense scratching.

An adult female louse lays about 6 eggs per day and can live for around 30 days. This adds up to about 180 eggs per louse. The longer the infestation goes untreated, the more eggs the adult lice will produce and the more they will hatch and develop into egg-laying adults.

Nits are very small and usually yellow or white in color. Because they are laid close to the hair shaft, they are often confused for dandruff or dirt. If you notice nits on your child’s scalp, you should check for live lice, but the presence of nits does not necessarily indicate an active infestation. If you don’t see any live lice, look more closely to see whether the nits have hatched and if they are more than 1/4 inch from the scalp — this indicates an old infestation that may no longer be active.

A live egg will have an ovular shape and be firmly attached to the hair follicle. If the egg has hatched, the shell will still be attached but it will have collapsed into itself — it might look slightly crumpled and will be white in color.

When they are alive, nits are firmly attached to the hair follicle close to the scalp. When treating head lice, it may be difficult to tell whether the nit is still alive or if it has hatched. The simplest way to tell is by looking at the color — live and dead nits are brown while hatched nits are clear. After applying a treatment to the scalp, you will need to check for nits and dispose of them in a plastic bag.

It depends on the ingredients used. Pyrethrins, for example, are generally recognized as safe but they will only kill live lice, not the unhatched eggs. As such, some over-the-counter lice treatments recommend you repeat the application after 10 days to kill any newly hatched lice. Check the label for whatever treatment you buy and ask your doctor if you are unsure.

Getting rid of lice takes time because there could be hundreds or even thousands of them in a severe infestation. The first step is to apply some kind of medication to the scalp to kill adult lice, nymphs, and eggs. About 8 to 12 hours after applying the treatment, use a fine-toothed comb to remove dead lice and nits from the scalp. You will want to avoid using regular shampoo for a day or two afterward and may need to comb several times as the medication does its job. Keep checking the child’s scalp for two to three weeks following treatment, repeating the application if needed.

This question is misleading because you can, in fact, get rid of lice, but there is no sure-fire way to 100% prevent a future infestation. In addition to removing lice and nits from your hair, you also need to remove them from your clothing, bedding, and household. Even then, you can still come into direct contact with lice from an outside source which puts you at risk for another infestation. That said, with the right approach and the right product (and a little magical help from the Hair Fairies), there are ways to help prevent lice.