In order to select the most effective and appropriate techniques to train behavior, we need to consider a number of factors: the animal’s natural history, its individual history, the animal’s function or role in the collection, exhibit constraints, and safety. Animal trainers must “do their homework'” as part of their training preparation and planning. A successful animal trainer uses knowledge of natural history, individual history, animal’s role in the collection, facility design, and an awareness of safety issues in developing and implementing a training plan. Knowing what is reinforcing or aversive to an animal, knowing the time of day when an animal is most receptive to learning, and understanding and recognizing the stress-related and comfort behaviors of the species are all critical to setting up the animal and the animal caretaker for success.