For weeks I've been mesmerized by the sky dance of Barn Swallows, whizzing above North Beach just a few feet from my Sit Spot. A group of swallows is called a "flight of swallows," just right for these remarkable birds. Never did they pause in their winged search for insects, until Wednesday when I saw a small flight of swallows seated on roots hanging from a cliff. Why were they suddenly so still? They were fledglings, puffing up their feathers and demanding insects from the parent birds, who continued their sky dance and in-flight delivery of insects caught for the hungry babies.