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 Lice have existed and lived side-by-side with mankind since the beginning of time. Lice infestations have been documented by every civilization in the world.
The cycle of a head louse has three stages: A nit, also known as an egg, is laid and then hatches into a nymph, also known as a baby louse, which then grows into an adult louse.
At many archaeological sites ‘nit combs’ have been found, including solid gold ones entombed with Egyptian mummies.
The classic symptoms of head lice are a very itchy scalp often accompanied by vigorous scratching. Infected persons often feel a sensation of something moving or crawling through their hair.
In some cases one may find red sores or superficial red bumps or bite marks that appear as small red spots, especially around the ear area and the nape of the neck, two of head lice’s favorite spots to hang out.
There are no health risks associated with having head lice, and they are not known to carry any disease. However, children may have swollen lymph nodes in the front and back of the neck due to excrement and bacteria in the saliva of these parasites.
Head lice do not like bright light so it is best to check in direct sunlight or under a bright light. Head lice can be very difficult to spot as they move quickly.
A nit, which is a lice egg are easier to spot as they do not move and stay firmly attached to the hair strand (after the eggs hatch the empty sac will still be attached to the hair strand).
The nymphs (or baby lice) are the hardest of all to see as they are very small and move very quickly.
The eggs are usually oval in shape and can range in color from white to off-white, yellow, brown or reddish. See diagram below:
Head lice feed on the scalp about five times a day by piercing the head with tiny hook-like claws.
They then inject a tiny amount of saliva into the head in order to keep the blood from clotting and begin sucking tiny amounts of blood.
During its lifetime, the female louse can lay up to 150 eggs at a rate of about 6–8 per day.
The life expectancy of a louse is from 3 to 6 weeks-from birth to death. This may vary with temperature, humidity, and climate.
The female lays eggs close to the scalp, usually no further than on the first ˝ inch of hair and may move down the hair shaft as they mature.
When an egg or nit hatches, it releases a nymph (or baby louse) while the nit shell (or egg shell) stays attached to the hair.
Nits (or eggs) usually adhere to one side of a strand of hair by a type of nit glue that the louse excretes when laying the eggs. As a result, nits (or eggs) will not move from the hair strand when the hair moves, gets wet, blown on, etc.
To check your child’s hair for nits, blow on it to see if these small dots that are often mistaken for dandruff move. If they do not move it is most likely a nit that is waiting to hatch into a nymph.
Lice crawl about nine inches a minute but cannot fly or jump. They spread by crawling from head to head, such as when two children are reading a book together and their heads are touching.
Lice also can “trapeze” from one person’s hair to another person’s as they have claw-like hooks that keep them from falling off hair. Lice are able to detach or let go from hair if they sense danger. Lice can crawl onto a coat, couch, bedding, etc. and wait for a new human host .
Lice are able to survive for about 24 to 48 hours before needing to feed on a human host. If no host is available they will die .
Eggs are able to survive between four to 10 days without a human host, virtually anywhere in your environment, while waiting to hatch .
After they hatch into nymphs, head lice will need to feed within 24 to 48 hours or they will die .
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