Animal testing on non-human primates between the monkeys natural behaviors versus the behaviors expressed by the diazepam induced monkeys in thirteen different locations inside the maze. Scientist Barros and his colleagues created this model to allow the monkeys to roam a less confined environment and slightly eliminate outside factors that may induce stress. Many of the best-known allegations of abuse made by animal protection or animal rights groups against animal-testing facilities involve NHPs. The so-called "pit of despair" was used in experiments conducted on rhesus macaque monkeys during the 1970s by American comparative psychologist Harry Harlow at the University of Wisconsin–Madison.<ref name="Blum1994/95">Blum, Deborah. "The Monkey
Northern pig-tailed macaque Northern pig-tailed macaque The northern pig-tailed macaque ("Macaca leonina") is a species of primate in the family Cercopithecidae. It is found in Bangladesh, Cambodia, China, India, Laos, Myanmar, Thailand, and Vietnam. Traditionally the northern pig-tailed macaque was considered a subspecies of the southern pig-tailed macaque, however they are now classified as individual species. In India, it is found in south of the Brahmaputra River, in the northeastern part of the country. Its range in India extends from Assam and Meghalaya to eastern Aruanchal Pradesh, Nagaland, Manipur, Mizoram and Tripura. A detailed report on the ecology and behaviour of northern pig-tailed