She wanted to pull the baby out of the cage. I don't think these are bad breeder rats, I think you need to study up on rat behavior and breeding. I don't mean this in a rude way, just stating plain fact. Are you putting the 2 males together with the females? That is a no-no. You mention 2 cages.. which ones are in which cages? What do you mean when you say they 'exercise together'? When a mom has pups she probably does not want time away from the babies until they're 3+ weeks old. I would encourage you to do some more research on the rats and learn from the behaviors you observe and then learn how to correct them with your own behavior. Good luck!