I live in the country and rodents are a constant issue. I've been around with all of the ideas and only one I'm finding that is working over a longer haul is strobe lights. I've installed Roxant strobe inside the RV setting them to blink every second or a little faster. The concept is that the flashing basically blinds the mice enough they move on. This has been a long term solution many places in attics. A link for the Roxant strobes: https://www.amazon.com/s/?ie=UTF8&ke...l_8fie696bqh_e
Since I've installed the strobes no more issues inside. I unplug these when we occupy the unit, the strobe blinds us too. These are 120 volt strobes, so unless you have shoer power at your storage site, it may not work for you. Our rig is stored beside our house with full power hookup.
In the basement areas I'm fixing to install 12 volt strobes that I can use even while at campsites. I'll post an update on these in the future. I've also sealed up all of the holes, down to 3/16" I can find, keep finding more holes.
Baited traps work well to get rodents already present, but yes the bait does attrack more rodents, it foods after all.