Aren't flying ants a very brief mating episode of some "regular" ants? If memory serves, it shouldn't last long. Hopefully, the annoyance to your hummers should be brief.

I do see flying ants sometimes, but only a few days if that long.

yardenman, I'm not positive that they are ants because I'm no entomologist. But they look exactly like ants to me, except that each has a pair of wings, and they fly. I have examined one closely: it is brown, has wings, is 1 cm long, and definitely has a "stinger." They've been swarming on our feeder for more than a week, and they seem to bother the hummers worse than wasps and bees do.