Rose Ordile: We recently trained the cat in a film called The Princess Diaries. Actually, we used three cats to play the part of one in that film. All of them were shelter cats. The majority of animals in the industry come from shelters or rescue groups, which I think is a very nice thing.
When it's a huge project, you'll use three to four animals to play the part of one because the animals have different personalities and sometimes there are so many behaviors for an animal to learn. You can't overload them. Also, they serve as a backup for each other in case one wakes up and says, "You know what? I don't want to do that today." They're not much different than we are. They have good days and bad days too.