Cat
With cats there is a limit to how far you can train them. They are at least as intelligent as dogs, but they are not pack animals. They like to do their own thing, and owners do best by fitting in. Never hit a cat: if you do, the relationship will never be the same again. If you really want to dissuade them, try hissing. It has been said that no one really owns a cat; many cats collect extra owners, and may change house if they do not like the treatment...