challenges in order to acquire the resources, such as food and shelter, that they require to survive. These challenges arise from interactions with other animals, or through changes to their environment that require the individuals to exercise their cognitive ability and to improve their behavioral strategies. Therefore, these challenges act as an important problem-solving element in the animals' day-to-day lives, and in-turn, increases their overall fitness. The animal anticipates positive benefits from a challenging situation which can directly affect its emotional processes. Cognitive enrichment should be provided in addition to a diverse environment that is already structurally and socially enriched; it goes beyond the basic needs of the animals. Social enrichment Social enrichment can either involve housing a group of conspecifics or animals of different species that would naturally encounter each other in the wild. Social animals in particular (i.e. most primates, lions, flamingos, etc.), benefit from social enrichment because it has the positive effect of creating confidence in the group. Social enrichment can encourage social behaviors that are seen in the wild, including feeding, foraging, defense, territoriality, reproduction, and courtship. Human-interaction enrichment The most common form of human-interaction enrichment is training. The human and animal interaction during training builds trust, and increases the animal's cooperation during clinical and research procedures. In addition, training sessions have been shown to benefit the welfare of both individually housed animals and communally housed animals by providing cognitive stimulation, increasing social play, decreasing inactivity, and mitigating social aggression during feeding. Assessing the success A range of methods can be used to assess which environmental enrichment should be provided. These are based on the premises that captive animals should perform behaviors in a similar way to those in the ethogram of their ancestral species, animals should be allowed to perform the activities or interactions they prefer, i.e. preference test studies, and animals should be allowed to perform those activities for which they are highly motivated, i.e. motivation studies. Environmental enrichment is a way to ensure that an animals natural and instinctual behaviors are kept and able to be passed and taught from one generation to the next. Enrichment techniques that encourage species specific behaviors, like those that are discovered in the wild, have been studied and found to help the process of reintroduction of endangered species into their natural habitats, as well as helping to create offspring with natural traits and behaviors. The main way