I had a meeting at 7 pm at Oakland Mills High School in Columbia this
evening, and arrived right at seven. After getting out of my car, I
heard the twittering of chimney swifts, and looked up to see 500 to 1000
swifts swirling around over the chimney. I stood and watched for the
next ten minutes as they funneled into the chimney -- the first time
I've seen this. Needless to say, I was late to the meeting!

John McKitterick