This has been a very helpful thread. I just had a female chew out of a tub last week. She chewed through the corner of the tub???? Still not sure how she did it, but I have a few theories. Working on catching her. She escaped but the other breeder female and six 4 week old offspring made no attempt to leave.
I am sad to hear that I will have to cull her, but at the same time it is nice to know that being more selective will save me $$$ in the long run.