They look nearly identical. However, the head louse stays on a person for its entire life, while the body louse lives in the seams of clothing and is only found on a person when feeding. The body louse is very rare, occurring in unsanitary, crowded conditions, where people wear the same clothing for many days. Head lice are the most common louse problem in the United States. They are easily spread by physical contact and infestations can occur under the best sanitary conditions.
Girls typically have higher rates of infestation than boys do.
However, having shorter hair does not prevent or eliminate infestations. Income level is not a factor in infestation. If one family member is infested with head lice, the risk of infestation for the rest of the family is greater. Usually Caucasians have more problems with head lice due to the shape of the individual hair shaft. Adults do not fly or jump from one person to another.