Nit(s) is a common name of a head lice (louse) egg. A female louse can lay up to 10 nits per day, and it usually takes about 7-10 days for them to hatch. If left untreated in a 30-day lifespan a louse can lay up to 100 eggs in her lifetime.
Nits get firmly attached to the hair fibers approximately 1.5 cm away from the scalp with a glue-like substance which makes them incredibly difficult to remove. The nit itself is a smooth oval-shaped structure that is attached to the side of the hair. They are similar in size, shape, and color of a sesame seed. Often dandruff is mistaken for nits, but because of their special adhesive, they are not as easily removed as dandruff would be.
Removing all of the eggs and disposing of them is the most effective way to ensure the eggs are dead. Nits can blend into lighter colored hair making them difficult to spot, so a thorough combing with a lice comb is recommended. If you find a nit that is further down the shaft of the hair and not close scalp is a good indicator that the egg is dead.
A child can have as little as one nit or several hundred depending on the severity of the infestation. Some treatments are unable to kill lice eggs, so be sure to use an effective lice treatment and perform a proper comb out.