Sounds like a great idea until they take up residence in your house.
They normally huddle in trees. But the eaves and soffits of your house are much better for huddling in to stay warm, because besides being cozy and secluded, they naturally collect heat during the day. It is a very annoying process to exclude the bats without killing them once they're moved in, and once they're out you have to immediately seal every opening over 1/4 inch in diameter or they'll come back. Yes, that small.