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
Macaque macaques have become invasive species in different parts of the world, while others that survive in forest habitats remain threatened. The long-tailed macaque ("Macaca fascicularis") is listed as a threat and invasive alien species in Mauritius along with the rhesus macaques ("Macaca mulatta") in Florida. The long-tailed macaque causes severe damage to parts of its range where it has been introduced because the populations grow unchecked due to a lack of predators. On the island Mauritius, they have created serious conservation concerns for other endemic species. They consume seeds of native plants and aid in the spread of exotic weeds