Bats and Bat Houses

We recently got a Bat House for bats because we thought it would be an educational experience - and it will be! We just have to hang in an ideal tree. Since we live in the country, we can put our bat house at the end of our property so we don't attract bats to the house, but suburbans cannot hang a bat house because generally, the houses are closer to each other. Speaking of, there is a bat "problem" in our roof of our house, and a humane exterminator covered up all the holes except one that they go in and out of. He covered that hole with a plastic bag, so last night we had to watch them come out and push away the plastic bag. They came out two or three at a time and flapped away to eat insects for the night, but there was about 10-15 that I saw come out. I was naturally fascinated, and watched them fly out, and I think they are Big brown bats or Little brown bats, they look bigger than little browns  though. The noises are above the master bedroom, which are flapping and "sci-fi" bat sounds. I don't find the noises freaky, but others, including some of the kids, do. Blaise and Benedict are okay with it, but Emerson isn't as happy. She was a little freaked out when she heard the noises, because she thought it was mice, but the noises we heard were not mouse-ish. So, we are ridding of our bat problem, and I'm sure tonight I'll take some pics for you guys. It really is cool but if we let it slide we could have damage and issues with the urine and population. (Plus, nobody wants to have bats flying out and in all the time! Our new Bat House is the only house we want the bats to be in!