Question
My neighbor's mom has a European Ash tree in her yard and we noticed the bark on the tree is peeling off she was wondering if it's normal for a tree to do that or if it has a bug in it.

Answer
It is not normal usually ash has a tight bark. I would think there is some type of wound associated with the peeling. either a mechanical wound or from an insect boring into the trunk. Borers will leave a dark colored wet spot where they make the damage. With out knowing more information that is about all I can do. I would cut the loose bark off and spray the area with an insecticide called Merit--this will kill any insect in the trunk and prevent insect attack if it were mechanical damage. A picture would sure help in identifying the problem.  Sorry that is the best I can do with limited information.