An overview of the results of a series of experiments that evaluated environmental enrichment for laboratory mice are presented here. The animal interacts with all these aspects of his environment. Cages for laboratory rodents should satisfy the physiological and ethological needs of, for example, resting, grooming, exploring, hiding, searching for food, and gnawing. The current environments of laboratory animals provide only the basic physiological requirements, such as nutrition and sanitation. Environmental enrichment, which provides a more structured environment, allows the animals to express more behaviors, that are within the range of the animals species-specific behavioral patterns.
Enrichment can focus on several aspects of the environment.
Mice and rats, being social animals, are often housed in groups, although this is not a natural way of living for the males. In some strains, especially in mice, aggression may give rise to problems, and the males have to be separated. Because humans provide the daily care, they are part of the social environment of laboratory animals. Another aspect to consider is foraging as part of the nutritional environment. In nature, animals spend a lot of time searching for food.