I had a bad get into my old apartment once, after I had joked about having a pet bat. I only discovered it when I went to the bathroom, with very little light, and it dive bombed me. That freaked me out. Especially since I had been hearing rustling and thought I was hearing things.
I did the catch and release thing. It came back though. That time I was so pissed I ended up killing it in my attempts to capture it (not intentionally). It's a good thing I hadn't adopted my dog yet, or she would have shredded the bat (being a puppy and all) I suspect.