I'm finally getting around to the rest of the story--don't worry, no more bats involved!
We finally got fed up with not having the air conditioners in the windows because we were afraid bats would get in again. It's been so hot & humid at night we can hardly sleep. I'm happy to say they are in, and we have had no further trouble. Here was our solution:
We got some metal screening and completely wrapped the outside of the units wherever there were vents & duck taped it one. Yes, we did this even though we know these vents do not connect to the front of the unit where it opens into the room. After installing them in the windows we put the foam piece between the two windows & taped that on with clear packing tape. Then from the outside, my husband packed foam rubber where the pieces on the sides stretch out and taped those.
After all that, my husband says, "well, they'd have to get through 3 layers of stuff to get in now & by that time we should be awake!"
Sometimes, I can't wait for Fall.