Excape from the rat rack

Well I had my first rat escape. The buggers chew a hole about the size of a silver dollar in the tub. How many have had this happen? I am debating weather to fix the tub or just go get a new one. The offenders are now in lock down. They will be spending the rest of their lives in a wire cage, if they live very long. I MIGHT give them one more chance depending on how generous I am feeling tomorrow. I am SO glad I didn't get rid of all my wire cages when I built the rack.

SO What do I do to keep them from all escaping? I am so not happy about this but I love my rack so I think I will still make my second rack, to different specs so I can use some metal tubs. Are there any draw backs from using metal tubs? LOL they won't be able to chew out of them!

i use the cement mixing tubs in my rack
i had a group of ASFs in one tub and they got a tooth on a little hole on the lip of the tub ( why its there..... not sure) they chewed chewed chewed and boom there was a hole a little bigger than a quarter in the tub

the fix:
i just took some 1/4 wire cloth and bent it up and over the lip, so now there are 2 layers of the wire cloth when you look through the hole. Then i took the wire that was wrapped around the roll of wire cloth and wrapped it around both layers along with poking holes on either side of the hole with a fork i heated up and stuck wire through that.
as far as i see, the chewing has stopped

now i do this to all of the tubs the asfs are in, hole or no hole