One of the main characteristics of social interaction is living in groups; in other words: living together. Animals gather together to optimize the profit of their environment. However, this environment is not always the same, and there are often local variations (due to physical, chemical or biotic factors, amongst others) that differentiate some groups within the same species, as they will present different grades of cohesion or interaction. Despite this fact, animals do benefit from a series of advantages by living in groups

Most primates do not shape their environment in an adaptive way.  They use it as it is without modification.  The sleeping nests of the great apes are poor, roofless constructions created for only one night.  Monkeys simply sleep on convenient tree branches without making nests.  No primate other than humans is known to store food.  They have a hand-to-mouth economy that forces everyone to seek food and water daily.