Back to the swarm. Dr. Tom Seeley says that to conserve energy, a swarm keeps its temperature too low for flight until the swarm is ready to take off. The scout bees grab hold of the low temperature bees and shake them to get them warmed up. I thought of this as I noticed the top of the swarm seemed to be "bubbling"—a lot of activity. As I trimmed around the swarm the activity increased, then the bees began sloughing off the sides and within a minute they were airborne.
Tanging: the beating on a pot or clanging a bell to induce a swarm to alight. The superstition persists, probably because it appears to work most of the time (especially when the swarm, emerging from a hive, is going to alight anyways). I had a pan handy, and no one around to see me make a fool of myself. So I tanged them out of sight. Good bye bees.