If you think you have lice and see a small, oval blob on a strand of hair, it's probably a nit. If nits are yellow, tan, or brown, it means the lice haven't hatched yet. If the nits are white or clear, the lice have hatched and just the egg remains. Lice eggs hatch within 1 to 2 weeks after they're laid.
Risk factors. Head lice are spread primarily by direct head-to-head contact. So the risk of spreading head lice is greatest among children who play or go to school together. In the United States, cases of head lice most often occur in children in preschool through elementary school.
Dead nits are often black in colour and are found well away from the scalp. Nits are laid on the hair shaft within 1cm of the scalp and take about 7-10 days to hatch into head lice.
About head lice and nits
Head lice are tiny, wingless insects that live in human hair and feed on blood in the scalp. Nits are the eggs of head lice. Brown-black nits are eggs that haven't hatched into lice yet. White nits are eggs that have already hatched.
They can be difficult to spot in your hair. Head lice eggs (nits) are brown or white (empty shells) and attached to the hair.
Eggs that still contain a louse embryo are brownish in color, while the empty egg shells are white to grey. As the hair grow approximately 1cm a month, eggs that are about 1cm from the scalp are more than likely to have already hatched or to contain a dead embryo.
The nits (eggs) hatch into lice in about 1 week. Nits (eggs) that are over ½ inch (1 cm) from the scalp are empty egg cases. They are very white in color. Off the scalp, nits (eggs) can't survive over 2 weeks.
Lice eggs (nits).
These look like tiny yellow, tan, or brown dots before they hatch. Lice lay nits on hair shafts close to the scalp, where the temperature is perfect for keeping warm until they hatch.
Nits are teardrop-shaped, laid close to the root of the hair and are glued firmly onto the hair shaft. Fresh eggs are a golden-brown colour and are plump and shiny before they hatch. Hatched or empty eggs are white and flat.
If you spot nits, but do not see any lice, it is possible that they are hiding and scurrying from the light as you search the hair and scalp; they can move quite quickly! Focus your search to their preferred hideouts, behind the ears and at the nape of the neck.
After each treatment, checking the hair and combing with a nit comb to remove nits and lice every 2–3 days may decrease the chance of self–reinfestation. Continue to check for 2–3 weeks to be sure all lice and nits are gone.
Live lice eggs are small brown or tan coloured dots on hair shafts close to the scalp. These can be incredibly difficult to spot. Broken egg shells, or nits, are easier to spot. It's common for parents to mistake nits for dandruff.
Head lice should not be considered as a medical or public health hazard. Head lice are not known to spread disease. Head lice can be an annoyance because their presence may cause itching and loss of sleep.
Head lice have six legs and are usually grayish-white or tan. However, they can camouflage, so they may appear darker or lighter to match different hair colors.
Then use a fine toothed “lice comb” to systematically work through the hair and remove adult lice. Regularly wiping the comb on tissues or paper towel will reveal the dispatched lice. This approach works but must be repeated twice, about a week apart, to break the life cycle of the head lice.
There is no way to look at a nit with the naked eye and determine if it is dead or alive. And although some people claim it does, popping them does not prove that one way or the other either. They are just too small. The only proof is when they don't hatch 7-10 days later.
After Treating with Lice Medicine
Use the nit comb to remove dead lice and nits. If some are still present but moving slowly, do not shampoo again. If lice are still active and no dead lice are found, call your health care provider. These lice may be resistant to the medicine.
The only way to prevent them from hatching would be to remove them with a good metal nit comb, or your fingernails. Nits are laid by the mother and attached with a glue she formulates, to sit on the hair shaft in the perfect spot to incubate and hatch.
Nits take about 1 week to hatch (range 6 to 9 days). Viable eggs are usually located within 6 mm of the scalp. ) and become adults about 7 days after hatching.
Lice take 9-10 days to become fully grown, feeding on blood. A female louse may begin laying eggs from 9 days after she has hatched. Therefore, in order to break the cycle, lice should be treated within 9 days of hatching to prevent any further hatching.
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.
But unfortunately, the nits will not simply fall out your hair. The lice themselves take 7 to 11 days to hatch, so after that what is attached to the hair is the empty eggshell or the dead nit. These will stay attached to the hair and as the hair grows you will find them further and further down the hair shaft.
Nits usually look yellow or white, or they can appear to be the same color as your hair, the CDC says. It's easy to confuse them with dandruff, scabs, or hair spray droplets, but nits tend to look like little grains of rice that are firmly attached to a hair follicle, Dr.