At least everyone can go home tonight and tell their loved ones of the sudden and extremely worrisome bat appearance
new thread http://mturkforum.com/showthread.php?33416-Can-t-Find-High-Paying-Hits-6-25-Thriving-Thursday!
There could be a colony in the attic crawl space, really it's kind of common. They do nest together like that. Often it's just a stray who wandered in though. I donned glove, tossed a towel over and tossed the towel into a bucket to remove the ones the cat brought in. I wasn't taking chances. But yeah they really aren't bad critters.
You are right they do live together, I was thinking more of traveling around. It's better to be safe because they do bite, I've seen Cujo.
I think I would be more worried about what killed it. Is your house built on an old indian burial ground?