I know this is a problem for some folks so, I thought I'd share how to prevent rodents from going after your wiring in your engine. The wiring contains soy and that entices rats/mice. The solution? Degreaser. I've been staying with friends in my rv in AZ for 3 years. I spray my engine wiring with degreaser about every 2-3 months and no damage. I did find a feeding area under the hood once, but wiring wasn't touched.
Hope this helps someone
Hope this helps someone