If you have a "mouse hole" to push your power cord into, the most effective way to keep them out is to install a detachable shore power cord. We have LOTS of field mice where we live and have never had a single problem with a mouse getting into anything. Maybe the mice in different regions are more aggressive? I did have a mouse get into a car once tho.
I googled "rat quarter" and only came up with French Quarter rats....
On rats:
I was building a house years ago and a rat(s) gnawed a hole in the sheathing (exterior wall) plywood to get in. I put a plywood patch back in and it gnawed through it again. Then I was in the basement one day and encountered a rat. It ran over to a corner of a room and stared back at me with it's beady little eyes. I quickly turned around a grabbed a cardboard box and tried to throw it over the rat. The flippin' rat got up on it's hind legs and made a terrifying loud noise. Scared the shoot out of me and I thought it was going to jump at my throat. Moral is, never approach a cornered rat. I then bought rat poison and the rat(s) was gone.
If a rat ever got into an RV, I would have to think it could do some serious damage.
