"Great stuff" makes a version of expanding foam that is designed for "varmints". I guess it tastes bad to them! It seems they would ALL taste bad to me, but you never know with mice. I had to seal the underside of my Solera in 6 places where the factory failed to completely seal openings cut for wires and pipes. Lead to mouse in the house syndrome. They chewed my heating duct runs under the kitchen cabinets. The way I identified the openings was to shine a very bright light under the rig at night, and look for projections inside where there was inadequate sealing. Took me three days to find them all. Some were so large I had to use wire mesh to create a location to attach the expanding foam to. Otherwise it would just fall down on me. If I didn't have safety glasses on at the time I'd have lost an eye! Dangerous stuff, that great stuff!
Ottawa Ontario Canada
2015 Solera 24R