I only speak from 1 year's experience. Last winter my Melbourne was parked outside at a commercial storage lot, sitting on gravel and surrounded by gravel. I made certain that every possible entry point was plugged with steel wool. All food items, even canned goods, were removed from cabinets. We put an entire box of dryer sheets throughout the unit - in storage bins, cabinets, under and around the couch, under the bed, even in outside storage areas. No evidence of rodent invasion. Hopefully that same procedure will work this coming winter.