Seems obvious to say that rodents like mice and rats as well as squirrels chew electrical wires.  It's always worth bringing up especially when you can see damage first hand and how serious of a problem it can become.  Packing leaf litter, fabrics and whatever else they can find to make a nest with inside of a wall makes for a dangerous concoction when they begin to snack on the wires supplying electricity to your home.  Pest control isn't just about remediating your current problems but also preventing them from ever becoming a problem again.  Pest control not only can protect yourself and others from viruses, bacteria and allergens but also will also protect your hard earned investments like your home.