I had a nearly-new Kubota
L3000 that "mice" chewed up some wiring in. I put mice in quotes because my suspicion is the culprits were either mice, ground squirrels, or chipmunks. I had to do a bunch of rewiring, then I put the wires in those corrugated wiring tubes [Home Depot, etc.]. After that, someone chewed through one tube, then so far never again. Had same problem with outdoor ham radio antenna wires. I also have problems with pack rats. No idea why rodents would be attracted to plastic-coated wiring.
Buddy of mine tried spraying his wiring with some of that bitter-apple solution that is supposed to keep dogs from chewing chair legs, etc. Each of us tasted the tiniest drop of it, and the taste stayed around for hours. However, mice still chewed his wiring again, seemingly zero effect from the bitter apple. By the way, I don't recommend trying the taste yourself.