I've noticed stripped bark on several trees in my neighborhood in the middle of Joliet, Illinois. Some of the damage has been near the base of trees, so I suspected rabbits. Now I'm seeing bark stripped from the upper branches of lilacs and other trees - too high for deer and certainly too high for rabbits, unless we have rare, tree-climbing rabbits. There are no "chew marks", just stripped bark. What could be doing this - raccoons? opossums?