Animal training refers to teaching animals specific responses to specific conditions or stimuli (刺激). Training may be for the purpose of companionship, detection, protection, entertainment or all of the above.

An animal trainer may use various forms of reinforcement (强化) or punishment to condition an animal's responses. There are many ways to train animals and as a general rule no legal requirements or certifications (证书) are required.

Chickens
Training chickens has become a way for trainers of other animals (primarily dogs) to perfect their training technique. Bob Bailey, former director of Animal Behavior Enterprises and the IQ Zoo, teaches in chicken training courses where trainers teach chickens to tell different shapes, to navigate an obstacle course and to chain behaviors together.

Fish
Fish can also be trained. For example, a goldfish may swim toward its owner and follow him as he walks through the room, but will not follow anyone else. The fish may swim up and down, signaling the owner to turn on its aquarium (鱼缸) light when it is off, and it will skim the surface until its owner feeds it. Pet goldfish have also been taught to perform more complicated tasks, such as doing the limbo (a kind of dance) and pushing a miniature soccer ball into a net.

Pigs
Among all animals, they are the third cleverest — monkeys, dolphins and pigs. Scientists think the training of pigs is easier than the training of dogs and cats. Pigs have a very good sense of smell. They can find things nearby or faraway. They can also help the police to find out drugs at an airport or at a train station.