Figure 55.8 Ectoparasites Hang On (A) Ectoparasites such as these whale lice on the body of a gray whale are flattened and equipped with strong claws for gripping the body of their host. Each individual whale has its own population of lice. (B) Grooming behaviors among primates are believed to have evolved in response to ectoparasites. Japanese macaques form social groups in which this behavior plays a significant role.