Every September, birds called swifts stop in Portland for several weeks on their migration south. And every time they pass through they roost in the chimney of the Chapman Elementary School. At dusk, people will gather to watch as the birds fly back to the chimney for the night. Thousands and thousands of tiny birds swarm back and descend into the the chimney. It almost looks like backwards smoke. We brought a big blanket and some pizza, and settled in to enjoy the show.