Question
I live in NC and have a huge shagbark in my back yard.  Recently, when I go on my deck it is covered in the tree's bark.  This is new.  I watched the tree from inside the house and it appears the squirrels and some birds are doing this damage.  Are they after bugs, will it damage the tree?

Answer
It does sound like a bird (wood pecker) after insects or a squirrel eating the bark. In either case it will not seriously damage the tree. The bark protects the cambium layer form damage and also hold moisture in the tree. Shag bark hickory has a thick bark and unless the damage it down to the wood it will not harm the tree--just make a mess. IF it is a wood pecker you can spray the trunk with a common insecticide like Malathion and this will kill any insects in the bark and the bird will go away. Squirrels are more difficult to keep away but usually as the season progresses they have less interest in the bark chewing.

In any case this is not harming the tree.