I searched to see if I had commented about this in an earlier discussion, but did not find my comment so I guess it was made about this subject on rv.net forums. In any event I hope this is not a repeat here.
We store our PC in an enclosed RV storage unit near our home. The facility is located in a heavily wooded area and is at the edge where the city meets the country.
There is a product called Tomcat which you can buy at Lowes, HD, Tractor Supply, etc. It is a package of green blocks about an inch square and two inches long of mouse/rat poisoning and is effectively used by farmers and ranchers.
I put one block on either side of each wheel on front and each set of wheels in the back....total of eight blocks. I have never had a mouse or rat problem. They obviously have to get up to the coach and the only thing touching the ground is the tires. Now, if you store outside that is a whole different situation and if you use it out there, you may kill some unintended critters. You can buy little boxes to put the stuff in with a hole only large enough for rodents but I wouldn't want to chance it with a dog in the yard.
By the way, I keep a couple of blocks in the garage at our home and a couple in the attic just to be safe. Our home is built on a slab and when we had a crawl space floor, I kept some under there as well.
Paul
Paul