I posted on the other forum but left something out that you are doing that is key. Giving the rats "things" to interact with and not overcrowding them is the key to a long lasting rodent tub. I've been using the same steralite tubs for about 4yrs...about 2.5 with the asf's in them and there is minimal chewing around the lid. I used wire but I rarely see mine hanging upside down long enough or near an edge long enough to chew on the lid.