The crab-eating macaque (Macaca fascicularis), also known as the long-tailed macaque, is a cercopithecine primate native to Southeast Asia. It is referred to as the cynomolgus monkey in laboratories. It has a long history alongside humans; they have been alternately seen as agricultural pests, sacred animals in some temples, and more recently, the subject of medical experiments. The crab-eating macaque lives in matrilineal social groups with a female dominance hierarch