I am fed up with mice chewing on the electrical wiring of my Kubota B7800, and of the nets they build. So I have found an answer which doesn't mean buying a cat! I don't know if the idea is new, most probably not, but it does work! I have found that if I pull up the rubber cone shaped cover on the steering wheel shaft I can get a small bag of moth balls hanging inside the dash board. I use a mesh bag, like the ones onions come in from the store, and be sure to use old fashioned mothballs (naphthalene) , Enoz makes them, Walgreens sells them. You can secure the bag around the steering shaft with a cable tie. The balls will evaporate after about a year, so replace them annually. I use about 8 balls. Also, hanging bags of mothballs in the apex of a pole barn keeps the wasps from building nests. And still more, it keeps mice out of the heat pump electronics, etc, etc. mice hate the smell of naphthalene Wonderful things, but everything will smell like your old grandmother...small price to pay. DON'T leave mothballs in an engine compartment or anywhere else that gets hot or has sparks...they are inflammable and heat from the engine could mean big trouble!