Lice are definitely not the sort of guests you want in your home. They won’t go away just because you want them to—in fact, if you do nothing, it is very likely that you, your partner or spouse, your children, your friends, and their friends will all eventually get infested.

Most schools have a “No Nit Policy,” though many experts believe it is unnecessary. This policy means that the school will not allow a child to attend unless they are free of any—and that means any—nits. There is actually a growing consensus that a “No Nit Policy” is an overreaction. Both the American Academy of Pediatrics[1] and the National Association of School Nurses[2] recommend against that policy, stating that children should be allowed in school once they have begun the treatment(s) to get rid of the lice.

In addition, while many parents, teachers, and nurses know that head lice have nothing to do with being “dirty,” there are still other kids out there who may bully, taunt, and humiliate a child who has head lice.

While it is relatively infrequent, kids scratching their heads can get secondary infections. These can range from fairly mild to pretty severe. You certainly don’t want to put your child at risk of even more discomfort and the need for further treatments.

All lice go through the same stages—the nit or egg stage, the three nymph stages, and the adult stage. But the three types of lice that are found in humans are each different species—hair lice can’t live or lay their eggs anywhere but hair, body lice lay their eggs only on clothing or bedding, and pubic lice can survive only on pubic or body hair.

Pubic lice (crabs) don’t carry any diseases, but can cause severe itching and sometimes allergic reactions. They can also cause secondary infections and can be very awkward and uncomfortable. They are much more common in adults and are transmitted by intimate, usually sexual, contact, but can affect anyone of any age who has reached enough sexual maturity to have some pubic hair. Pubic lice are considered a type of sexually transmitted disease (STD) by the Centers for Disease Control and Prevention (CDC). Pubic lice may sometimes be found on the legs, armpits, mustache, beard, eyebrows, or eyelashes. Generally, if pubic lice are found, testing is done for other STDs. Treatments for pubic lice contain chemicals (mainly pyrethrins) that act as insecticides.

Body lice are a different animal than either head lice or pubic lice. Body lice live on bedding and in clothing and lay their eggs there. They come onto your skin to feed several times a day. Body lice, unlike head lice, can spread diseases such as typhus, trench fever, and louse-borne relapsing fever. Epidemics of typhus are not common anymore, but there are outbreaks in prisons and in areas suffering through war, unrest, chronic poverty or disasters—anywhere people have restricted access to showers, baths, and laundry facilities. Body lice are transmitted by people living in close quarters, but access to showers and baths as well as laundry facilities is usually all that is required to treat body lice.