Environmental enrichment can be beneficial to a wide range of vertebrates and invertebrates such as land mammals, marine mammals, and amphibians. In the United States, specific regulations (Animal Welfare Act of 1966) must be followed for enrichment plans in order to guarantee, regulate, and provide appropriate living environments and stimulation for animals in captivity. Moreover, the Association of Zoos and Aquariums (also known as the AZA), requires that animal husbandry and welfare be a main concern for those caring for animals in captivity.