I built this bat house a few years ago, based on information on some bat expert web sites. It has 3 chambers (like 3 vertical "floors") and will hold 100 bats. Bats like it hot so put the bat house about 12 feet up on the east side of a building so it catches the morning sun. This does nothing to stop them from flying around wherever there are mosquitos, so it isn't going to help your problem unless they are nesting in the house.