Anti Rat Pro Spray is good for keeping rats and mice away and keeps them from chewing up wiring and hoses. It is a hot pepper based product that spices up rodents lives and keeps them away.
Some bird seed products have ground red pepper added to it to keep squirrels from getting into it. Birds are immune to the spicy heat of hot peppers so it doesn't bother them.
The spray can be used on vehicle hoses and wires to keep rodents from chewing them up. It is also sprayed around under the rig and in the engine compartment to ward off the unwanted wanted guests.
I know of a couple full time RV nomads that have had mice chewing on their wiring and getting up into their engine compartments that swear by the spray. They also raise their hoods and place a light under the engine compartment at night.