Hmmm.......your MI barn bat is 2X the size I have here. I have about a dozen that roost in a small cubby hole in the corner of the house eves. I pulled off the eve board and sectioned off a small portion with expanding styrofoam. It's just the right size for this little group. Put the eve board back on - now they have their own little bat house.
They have a tough job this year. The mosquitos are numerous and vicious.
Buy or build them a house or houses. Keep it away from an area you spend evenings at, but near where you want the bugs eliminated from. They will move in. There is quite a flock behind my barn shutters and in several houses I've put up behind my house.