Fred,
Rodent damage (rats, mice, and squirrels) can be the most expensive repair that you ever make on a coach or car. I have seen engine damage caused by rodents chewing through an inlet hose between the air filter and the turbo, and an engine fire from a nest on the exhaust manifold not to mention all the wiring damage. Therefore, you really need to keep them out of your coach. Unfortunately, the only foolproof method that I know of to do that is by driving it. I have never seen a rodent that could catch a coach on the interstate, but I have seen several parked beside the interstate waiting on a tow truck due to rodent damage.
Gerald