Squirrels and other rodents chew where they smell food. Seeds from trees and bugs will give them reason. Modern plastics and wire insulation is not of interest to the animals. but may be a barrier to a food source. So this a motivation to clean out the tree and plant residue that collects in the corners under your car’s hood.
My dad use to have Bird feeders that he watched during the day when he was retired. The squirrels would chew on the feeders to get at the seed, and only wrapping them in High voltage deterred them. He did comment that the squirrels would have a very surprised look when the bit into the ground return wire on the outer edge of the clear shield. Is set the power wire up to only deliver a harmless zap. He didn’t want fried squirrel attracting other animals.
Lucky cats!