I have a group of three females that went through three or four tubs by chewing a hole in the corner. After I saw the last tub I realized that they never escaped and only chewed the hole to around the size of an egg. I've kept that tub with the hole for about 3 months now and haven't had any problems with them or their young trying to escape, but I make sure not to move them to other tubs so they can teach other rats.

I guess they just wanted a room with a view.