It is the trainers job to find those skills and develop them. If you own, or have owned, a dog or cat you will have seen this yourself. Certain breeds of dog, poodles for example, naturally walk on their hind legs without prompting. Hold up a treat and the dog will stand up on its two back legs and start to walk toward you - letting you know he wants the treat. If you make it a game and show the animal you are pleased and excited that it did good, make a fuss of him and reward him, then the animal will learn quickly and will soon do its trick when you ask it.
More intelligent animals can learn whole routines of many tricks.
For an animal in the circus, showtime becomes playtime. In this section you will learn about our elephants, horses, tigers, and Boo Boo our magic dog.