Lice eggs are so small you would never know if they hatched or not. The only way to prevent them from hatching would be to remove them with a good metal nit comb, or your fingernails.
You can't completely prevent getting exposed to lice but by doing a combing head check twice a month you can find a few nits before that person is contagious stopping the spread of lice.
You also have the option of using petroleum jelly, mayonnaise or olive oil to wet the hair as an alternative to using water. It is believed that these substances have the ability to prevent lice after exposure, because the chemicals in them help suffocate the lice.
Machine wash and dry clothing, bed linens, and other items that an infested person wore or used during the 2 days before treatment using the hot water (130°F) laundry cycle and the high heat drying cycle. Clothing and items that are not washable can be dry-cleaned OR sealed in a plastic bag and stored for 2 weeks.
If wet combing has not worked or is not suitable, you could try a medicated lotion or spray. These kill head lice in all types of hair, and you can buy them from pharmacies, supermarkets or online. Head lice should die within a day. Some lotions and sprays come with a comb to remove dead lice and eggs.
Off the host, adult head lice can live about two to four days at 74 degrees Fahrenheit (F) and one to two days at 86 degrees. Nits will remain alive off the host for up to 10 days; they will not hatch at or below room temperature (68 degrees F). How are head lice infestations treated?
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.
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.
Treatments for lice typically involve OTC or prescription medications. These treatments typically kill live lice but do not affect the eggs. This means it may take several treatments over 2–3 weeks to eradicate head lice. People can speak with a healthcare professional for further information about treating lice.
Just like with mattresses, lice can only live on any bedding—whether it's sheets, pillows, or comforters—for 1-2 days. Without a human scalp as a source for food (blood) for longer than 1-2 days, lice cannot survive.
What makes someone contagious with head lice is having a mature, egg-laying adult female louse on your head that could travel to another head. After the first treatment, when the egg-laying lice are eliminated, you are no longer contagious.
For the study, researchers compared tea tree oil, lavender oil, peppermint oil, and DEET. The researchers found that tea tree and peppermint oil repelled lice the most, and a tea tree and lavender combination kept some lice from biting people with treated skin.
Hair products such as hairspray and hair gel don't necessarily help to keep head lice at bay. It's also important that you think about the amount of chemicals in hair spray and whether these are good for your children.
Nymphs mature into adults about 9–12 days after hatching from the nit. Adult: The fully grown and developed adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. Adult head lice may look darker in persons with dark hair than in persons with light hair.
It is not usually possible to get rid of lice in one day, as an infestation needs to be treated. However, there are treatments that can help get rid of lice and symptoms caused by lice more quickly.
Continue to check hair and use the nit comb to remove nits and lice every 2 to 3 days for 2 to 3 weeks. This process should be done for as long as nits and lice are still found on the head. Many lice medicines recommend a second treatment in 9 to 10 days.
Malathion lotion, 0.5%;
Malathion is pediculicidal (kills live lice) and partially ovicidal (kills some lice eggs). A second treatment is recommended if live lice still are present 7–9 days after treatment. Malathion is intended for use on persons 6 years of age and older.
A louse goes through three stages: Eggs that hatch after 6 to 9 days. Nymphs, immature forms of the louse that become mature adults after 9 to 12 days. Adult lice, which can live for 3 to 4 weeks.
As with furniture and carpets, adult lice typically live for around 2 days on pillows and sheets without human contact. Nits will not hatch and will die within a week. People should machine wash any pillows or sheets someone with lice has used in hot water of more than 130°F (54.4°C) .
Head lice sometimes go away on their own because there are not enough insects to maintain the infestation, or they may persist for an indefinite period without treatment. With proper treatment, the infestation usually goes away within about two weeks.
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.
Children can have a few nits without actually having a case of head lice. Usually children have no more than 10 to 20 live lice.
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.