Probably. Part of the problem is that many modern electrical insulation materials--in an effort to be eco-friendly--are made of soy derivatives. When such materials are used for wires in car engines, as they frequently are in Japanese cars, rats consider them dinner. I live in a rural area, and I've spent many $K on this problem.

Whether there's an equally "natural" material that rodents don't like is a question that should be researched.