I have bats, too. Unfortunately, I think they're roosting in the attic.
I'm going to put up more netting over the ventilation holes in the brick. That way, they'll have to find somewhere else to roost.
It's not like I don't have several buildings on the property that they can use! They sure as heck don't need to be in the attic.
I love having them around. I enjoy watching them swoop and fly, gathering bugs for dinner. If you have a safety light, they'll congregate there and decimate any bugs hanging around.