bats in out belfry
We have bats living in our house. Now, it is possible to build or obtain such a thing as a "bat house", but we skipped that step and just let em into our own house here. They're pretty good tenants; we hardly notice them except for occasional periods of skittering and scratching when their fighting or mating or, I don't know, just trying to get comfy up there. We could wish their nest was somewhere other than directly above the head of our bed, but that's alright. (We also assume that they are doing no damage to our house, which I hope is in fact the case.)
I enjoy watching them fly around every evening when I'm out with Rascal, flitting and squeaking (I imagine) and chomping up the mosquitoes (I sincerely hope). I just wish one would slow down long enough for me to get a close look at what it actually looks like!