Lice are an insect that live on animals with fur, hair or feathers and feed on the animal's blood or skin. Typically lice attach their eggs to a host animal's fur. These eggs are around 1/16th of an inch long and usually hatch within 7 to 10 days. After hatching, lice, or a single "louse" will take about 10 to 12 days to mature and are gray in color and darker after feeding on blood. Lice are fairly hardy creatures and have a poor temperature range. Most lice die if they are exposed to 130 degrees Fahrenheit for more than 5 minutes.
3 types of lice infect humans, head lice, body lice, and pubic lice. Head lice commonly infect children and are spread in school. There is little schools can do to stop the spread of head lice so parents need to notify the school as soon as they discover an infestation while protecting their child from humiliation whenever possible and treating the condition immediately. Usually people who are infected have itchy scalps and lice eggs can be found attached to the hair when the scalp is closely inspected. There are two main treatments for head lice, lice combs and lice shampoos. Lice combs, also known as nit combs, have very fine teeth so that only single hairs can fit in between and eggs are pulled off. Lice shampoos are the most effective treatment and usually kill all of the lice and most of the eggs when used properly. One last solution that requires a more willing patient, but is very effective is shaving the head. By cutting the hair less than one inch long, the environment becomes too cold for lice to live and also does not require the use of any chemicals.
Body lice are the only lice that are known to transmit disease. Because of this body lice can be a serious health threat and those infected are at risk for typhus and other bacteria infections typically ending in "fever" such as "jail fever" or "trench fever". Instead of attaching eggs to hair, body lice attach eggs to clothing. The actual lice themselves also usually stay on the clothes as well. Often body lice are found in areas where there is overcrowding and little clean water. Sharing dirty clothes or sharing dirty beds is a common cause of infestation. Usually body lice can be destroyed simply by boiling clothes and bathing. Infected individuals will be able to tell whether the lice have been cleared by whether or not their skin continues to be irritated. Also some individuals, often those with more body hair, may have to be treated with insecticide to totally remove the body lice.
Pubic lice are slightly different than head and body lice. The first difference is the appearance. Pubic lice do not have a large abdomen like head and body lice; instead their body is round, which gives them the nickname "crabs". Another difference is that pubic lice attach themselves to hairs as well as their eggs. While most commonly found in pubic hair, pubic lice can actually survive on most body hair sometimes even as small as eyelashes. The lice are also fairly hardy and can survive up to 24 hours without a host. This makes them able to transfer among people in a variety of ways. Most commonly pubic lice are transferred through sexual activity; however they can also be transferred by sharing bedding or blankets, or by coming in contact with infested toilet seats or clothing.