Yep, we had bats for a couple of years. But the box was up a few years before that. A neighbor who was retired as a forest ranger and was something of a naturalist gave specific instructions on how to make it and how high to hang it and how close to water it had to be to attract the bats in our area.

Apparently the bat species in my area have to have open water within 150 yards or something. It was fifteen years ago or so.

I didn't do anything special other than keep a mostly organic yard.