Pediculosis, or head lice infestation, has been a public health nuisance for thousands of years. Since most affected children are under 12 years of age, head lice is an elementary school issue. The question then becomes how schools should handle cases of head lice. Some organizations advocate immediately sending children home from school, while others contend that keeping these children in school is more important. Many schools and districts have a strict "No Nit" head lice policy. In other words, if a nit, or egg, is found, the child must immediately be sent home, and can return only when he or she is nit-free. That is also the position of the National Pediculosis Association. However, opponents of "No Nit" policies argue that there is no need to send infested children home from school. The National Association of School Nurses, in fact, recommends that schools eliminate their "No Nit" policies. Its reasons include: The Harvard School of Public Health discovered significant misdiagnosis of head lice; students who are sent home miss valuable in-school instruction; and removing students can lead to teasing. While adhering to a "No Nit" policy helps curb or prevent an outbreak of head lice, it may needlessly keep children out of school. Schools must develop head lice policies that help children and parents control the infestation, while keeping children in school as much as possible.