sentences:  The goal of environmental enrichment is to improve an animal's quality of life by increasing physical activity, stimulating natural behaviors, and preventing or reducing stereotypical behaviours.Also the use of behavioral training, as another method of behavioral enrichment, has often contributed to the animals well-being as well as allowed zoos to improve dramatically their ability to care for animals, while reducing animal stress and increasing safety for both keeper and animal during care procedures.It is self-evident that such training must be done by expert keepers in a way that is appropriate to the animals, based on biological and scientifically sound learning principles.