The Role of Play in Rat Behavior

Rats are the most studied animal in terms of play behavior. They're very playful for about four or five weeks of their life before they really hit adult adults. And so if you take a two rats and you raise them in isolation, but then give them play dates half an hour a day or something, they'll just engage and play almost continuously for that period of time. No one has to teach them, they know what to do.