There’s some debate as to why rodents chew car wires. First, many pest experts agree that chewing is a biological instinct for rodents. Their teeth never stop growing, and chewing on objects, including car wires, is a way to trim them.2
Additionally, rodents may be attracted to your vehicle because they need a place to stay safe, warm, and dry to hide from predators and inclement weather. Your car provides the safe space they need, and they find your wires in the process.
A final, heavily debated theory about why rodents chew wires is that they like the taste. At some point, vehicle manufacturers began using soy-based wiring in cars. Some people theorize that these wires taste good to rodents, and that’s part of why they chew them.
Not all experts believe this theory. However, it’s popular enough that in 2018, Toyota was on the receiving end of a class action lawsuit for using soy-based material in its wires that attracted rodents.3 A judge threw out the case,4 and while an appeals court later overturned that decision,5 the case was dismissed again in August 2022.