Lice are a parasitic insect belonging to the order of Phthiraptera. An infestation of these creatures is called pediculosis. Lice feed on the blood of warm blooded animals, and live in their hair. They can live on almost any part of the body that has even a small amount of hair. On humans they usually live in the hair on our heads, though pubic and body lice are also known to exist. Luckily, for the people with pediculosis, there are many ways you can get rid of lice.
A infestation of head lice on humans is known as pediculus humanus capitis and is most common on human children. Children between the ages of three and ten are considered the most susceptible. Young girls are also significantly more likely to get it than males. This is because girls usually have much longer hair. People of Afro-Caribbean or black descent usually have a lower rate of getting lice as well. This is because their hair consistency isn't nearly as conductive a living habitat for a lice infestation. Even if these children have trouble getting full infestations, they can still carry nits(lice eggs), which can spread to other adults and children.
Head lice are only spread through head-to-head contact. Lice cannot jump significant distances and cannot fly because they don't have wings. Lice can also be carried in clothing and other personal items. Hats are notorious for carrying head lice. Body lice are more likely to be spread through clothing. Most body lice live in the clothing of an individual rather than their actual hair(they do attach their eggs to hair however).
There is no gurantee that any treatment for head lice is going to work one hundred percent of the time. This is because lice treatments usually can only kill the living lice but most cannot kill the eggs as well. Treatments can still be used to great success however. There are chemical pesticide treatments, some very effective natural based methods, medicated combs, silicone based lotions, and shaving all of your child's hair. Shaving is not recommended by some experts however, especially for young girls. Completely removing a child's hair can have detrimental psychological effects on some children.
Because most lice treatments fail to kill the lice eggs on the first treatment, they must be repeated atleast once every ten days. Lice eggs can take six to nine days to hatch so the treatment must be repeated to kill all the living lice before they can breed and start laying eggs again. Some treatments also say you should have a 3rd treatment five days after the second. What it really comes down to is to follow the instructions for each specific treatment option carefully.