rat AND mouse growing bin

has anyone kept weanlings to subadult mice and rats together for longer than a week? I've kept them together for short time periods when relocating them but would like to keep them together in a grow out bin for a month or so. is that possible or do I absolutely have to get separate bins?

Get separate bins; rats are predators and it will only be a matter of time before they attempt or succeed at killing the mice. Then all your hard work growing up feeders is down the drain.

Yeah, separate them asap. They are natural enemies like lions and cheetahs, they compete for the same foods.