Penn likes to say that a lot of magic boils down to no one really believing anyone is going to spend the time and resources to do the obvious thing. Magicians are people who are willing to spend the time and resources to do the obvious thing.

Like people who seem to swallow things and then reproduce them later. The easiest method to do that is to swallow the thing and then regurgitate it. And you can train yourself to do this. But it takes time and effort. And is a little gross and if you're working with live animals, you are also on a time limit.