I'd run even FASTER now! You initially mentioned 'droppings' in your first post. I think it's possible that the droppings may be from termites and NOT from bats.
Dry wood termites are different from sub-terranian termites in that they don't need moisture for a source. They use wood for both food AND housing, whereas a carpenter ant, for example, uses wood for the home and brings in outside food. Since you CAN'T see the damage to the inside of the wood, who knows what its condition is.