The only thing I've seen rats not chew through is steel wool, but they still give it hell. Wood. Rubber. Plastic. We used to have this gopher rat at my old job, Leroy, that joker delaminated a door and peeled up the carpet, which was glued down with vct tile glue, to try and get in our break room. When he failed that, after what I can only describe as hours of laborious work, he said fuck it, and proceeded to go through a double sheetrock wall right beside it.