Cliff Swallows ~ It was fun watching the swallows gathering mud for their nests, zipping around, back and forth.
Cliff Swallows Flying ~ I've never been able to photograph swallows in flight, as they fly so fast, and dart and swoop around so much. At the "mud hole" they were flying in and out, and I had some change to capture them in flight.
~ While birding in Imperial Beach, near San Diego, CA, I ran across a large number of Cliff Swallows harvesting mud for home-building. They were flying in, digging up mud in their beaks, and flying off to continue in the hest-building process.