One night I was awakened by the loud call of a katydid, next I heard the noise of claws on the screen and a soft whoosh of wings. I looked towards the sound and saw a creature flying around the room in the dim light from the streetlight. It took me a while to register that it was a bat, but when I did I yelled for Dean to wake up (he can sleep through anything) because there was a bat in the bedroom.
I then jumped out of bed and said I’d gather the cats and hide in the bathroom until he got rid of the bats because I was worried the cats would try to catch the bat.
According to Dean he spent the first few moments hiding under the covers. The way he tells it, he’d take his head out and the bat would swoop towards him and he’d hide under the covers again. Then he got up and opened all the windows in the house and the bat flew out.
Cedar Waxwing's 365 
Oh, that “soft whoosh” is scary! If I opened all the windows in the house I’d be afraid something would fly IN. My cats killed a bat in the house a few years ago. I came home one night and found it (and them) in the upstairs bathroom. They’re indoor cats, and I couldn’t remember if their rabies shots were up to date. Turned out they were, but I got them booster shots anyway.
One does worry about more flying in, but I’ve never thought the bats wanted to be in. They are just as freaked out and just want to get out!