I honestly think they can get through anything if they want to bad enough. I had a buddy who worked construction for decades, every facet of it, but he specialized in concrete and he swore they could actually chew through concrete given enough time and will power. I brought in 5 vehicles from very heavy woods and it was amazing how many rode the car hauler and stayed in their condo. I was killing them left and right with the pressure washer, I'd stun them enough that I could run up and stomp them to death. Some, it would kill outright. One long wheel base Apache was just gone from rat pee, all up around the windshield, floorpans/cab corners, everything just eat up for the acid from their pee. I went through several gallons of Purple Power and stuff like that and tore out all the interior that was gone anyway, to keep them as dry and vermin free in storage as possible. Really about the best thing is roaming feral cats or sticky traps with peanut butter or hot dog chunks stuck in the middle.
