Recently I found a decent-sized group of Cliff Swallows nesting under the side of a bridge. I sat and watched them for awhile as they swooped out as a group to snatch bugs out of the air and bring them back to their chicks. I read that both parents feed the young, which could explain why so many of them clustered around the nests, but in some cases one of them would try to fly to one nest, get turned away by some of the others there, and then fly out to a different nest and stop there.
They were fun to watch; swallows are very aerobatic, taking sudden turns and diving through the air. I tried taking some pictures, but the whole scene was better captured on video. Plus, I got to try out slow motion, although that camera can only record a few seconds of slow motion video.