Gloved hands lift the hivetop, far far above the departing bees. The fingers in the gloves feel warm. The bees hear the warmth. Some do, anyway... but don't know what it is, and band their wings against the comb, to drive away the intrusive sensation.     I didn't really understand what was going on until the first time it seemed to happen to me, one afternoon, when I went out to the backyard, to open up my hives.