I have built in rodent deterrents. Since I switched from a metal roof to an asphalt roof last year, my cats are always on the roof. I'll hear something and look up and see cat heads peaking in at me from the skylights. Only down side is one of the cats has now caught two bats up there and brought them inside. Luckily dead. Unfortunately they like to bring in live chipmunks and then set them free in the house so they can play with them. Kinda weird how they kill the birds, bats, mice and bunnies, but not the chipmunks. Half the time it's the dogs that end up killing the chipmunks.
Having cats to keep pests out is good. My house doesnt have easy access to the roof so now I have a wire net around the entire system. Along with spikes and reflectors.