Bats aren't exactly known for their chewing activity, so if you have signs of chewing on your property or in your yard, the evidence is pointing to another culprit; probably a rat, mouse, squirrel or similar.
Bats do not chew. They won't chew through your electrical cables, lighting wires, attic insulation, wooden beams or foundations, ductwork, or anything else that you may find on your home. Bats usually have such teeny-tiny teeth, you wouldn't even feel them if they bit you half the time, so to expect them to leave evidence of chewing behind would be expecting a lot.
Bats can destroy these areas in other ways. Just because they don't chew doesn't mean that your wires and cables aren't at risk. Urine and guano (bat droppings) can have a massive effect on electricals and other items that it comes into contact with, and this is the case with the feces and urine of most, if not all, wild animals. The thing you need to remember about bat poop is that it is a very corrosive substance — high in acidity. With enough of a buildup, there is a chance that the acid content could burn through materials, even the floor of your attic if the problem is left there for long enough. It'll certainly build up to an unpleasant sight and odor, that's for sure.
Can bats chew though spray foam, wood, or screen?
If you have a chewing animal, but you also can see signs of bats, you have a double pest problem. This can happen easily — one animal attracting another, and it tends to happen a lot when the initial animal control problem isn't resolved quickly enough. Although dead and injured bats are usually kicked out of the roost, dead carcasses could still be left lying around, and this will attract scavengers and rodents after a while, and perhaps even flies too.
Go back to the Bat Removal
page, or learn about bats in the attic with my Bats in the Attic
guide. Or read What do Bats Eat?