I live in a 1903 home that was a bat haven when we moved in. If you have found two bats in your home, I can tell you that is not the only two you have. Your attic, or if you have knee-walls, etc, is probably full of them. They can squeeze into the tiniest of places. For our problem, we plunked down $500 about 12 years ago and paid a company that just specialized in bat removal to remove our bats. They are able to see tell-tale signs of where they are entering your home. They will then insert a special item that will allow the bats out, but not back in. Bats will leave at night, but then they cannot return. It is the most humane way to address them, in my opinion. and we have not had one bat since. We used to hear them scratching and squeeking when they were in the spaces between our roof and ceiling.
By the way, if you have a few bats that have gotten from your attic into your home, you have to shag them out. We had one land on a shoe and we simply took the shoe outside and waited until the bat flew out. A couple of others we trapped into a tuperware container against a wall and then took them outside and shook them out. They are scary-looking things and creeped me out when they got into our lving spaces.