I use mothballs in our Scamp
when not in use. The smell gives critters a headache. When we travel I have to keep the mothballs outside - my DW does not tolerate the smell either.
Also I hang a bag with a few of those in the engine compartment of our cars. My truck had some sensor wires chewed once by chipmunks and it cost me $200 and a delayed departure on one of our camping trips. The delay bugged me more than the cost.