These bloodsuckers are closely associated with humans, and different subspecies reflect the place where you can find them: Head Louse (Pediculus capitis) or Crab Lice (pubic Pthirus) are an example. The most impact from a public health point of view is undoubtedly the first. Lice was a seasonal plague usually appear in spring / summer. At present, we can find them throughout the year. They can run 25 cm. per minute, but do not fly.