To rats? In that it isn't a real world demonstration? You are using rat as guinea pig it seems.

The level of motivation is different, but the incentive to cooperate is still comparable. If both criminals keep silent, they have a better change to not get convicted, and possibly go free. If one "rats"/talks about the wrong someone else did, then they get to go free, but if both "rat" on each other, they both go to jail for longer times than both shutting up and cooperating. The prisoner's dilemma game works ont he same principle.