The bat situation

Last night, after we went to bed, The Real Grendel started crying, so I went downstairs and let him out. I opened the kitchen door and off to my right noticed something dark, a blob where a blob shouldn't be, fastened to the bottom of a picture. I had taken off my glasses and couldn't make out any details as I approached the thing to study it. It seemed to be some sort of gigantic insect cocoon or perhaps an alien pod. But I knew in my heart it was a bat.



I ran upstairs to get my glasses, but when I came back down and rounded the corner into the kitchen, it was no longer there. Instead it was flying around the kitchen. It was horrifying and fascinating -- really impressive the way it was completely silent, and the lighting made its wings sort of glow brown-orange against the ceiling and walls. Then I watched it fly upstairs.

"NNNnnnnno!" I grabbed a broom and chased it, but it was too fast for me. Four of the five upstairs rooms had their doors open, including the bedroom. I started there, flipping on the light and explaining to a curled-up Tracy why I was poking the curtains with a broom.

"No way."
"Yes!"
"A bat."
"A bat!"

I could not find the bat anywhere. I finally gave up and, uneasily, went to sleep.

This morning, The Real Grendel woke us up whining and apparently watching something fly around the room, though the light was too dim for me to make anything out. We all went back to sleep, and later I let him out again. When I returned upstairs, I saw the bat in our bedroom window:



It's hard to tell in this photo, but it somehow managed to squeeze itself into the half inch or so between the storm window and screen, still very much alive. Due to the configuration of the window, I cannot raise the screen to let it out and I cannot lower the upper window. I can only close off the whole thing by closing the window. The only escape seems to be back into the room. I don't want to call an exterminator because it seems a waste of money. Why should it cost me $40 or whatever to get a bat out of a window?

I am at a loss about how to capture the bat. I don't want to hurt it. Any ideas?

UPDATE: CRISIS RESOLVED, SITUATION NORMAL
After declining a $299 offer from a pest control company, I called Iowa City Animal Control. An officer showed up an hour later, a skinny, no-nonsense blonde woman in a uniform, who was holding a square tupperware container on which was written "BATS," in black magic marker. It had air holes poked in it.

I nearly chuckled at her naivete. Surely she should be wearing military armor and be wielding an industrial-strength vacuum cleaner? But whatever -- it was her life, and if she wanted to show up unprepared, nothing I could do about it. Besides, the service would be free. I was only worried that she'd be fiddling with the thing for hours, and I didn't have hours. We went upstairs.

She looked at the window and asked for a coat hanger, which I gave her. Then she opened the window about halfway. Then she dragged the bat down inside the window with the coat hanger while holding the "BATS" tupperware container underneath it with her other hand, until the bat fell into the container. Then she put the lid on the container.

"Wow," I said. "Thanks! You do a lot of this?"
"Oh, forty a week, maybe."
"Ever been bitten?"
"Not by a bat."
"What will you do with it?"
"Let it go, far away."