We recently moved to Oregon from Southern California where we stored the coach inside. In Oregon, I had to store the coach outside so after a brief encounter with some mice leaving their calling cards, I did a search on this site for mice related topics and Mouse Free came up as a recommendation. I didn't like the application process but during my research, I came across peppermint oil.
Mice apparently cannot see well but depend on their smell as their major sense. Peppermint oil destroys their sense of smell so they stay away from it.
I put about a dozen cotton balls around the inside of the coach, three in the engine compartment and one in each bay. I place about ten drops of peppermint oil on each cottonball and I'm done. It seems to work perfect and the coach always smells good, and when I go back to do my monthly generator exercise, I refresh each cottonball again.
It works well for me and there is absolutely no sign of mice.
The peppermint oil can be purchased at any vitamin store.
Good luck and I hope this helps.
2023 Cougar Trailer
Joe & Judy