We had an abundance of hummers this summer (hmmm, sounds like the name of a boat!)
We put up three feeders in different locations to accomodate them all. Even so, one dominant male often rules over each feeder and chases other males away. We changed the sugar water weekly to make sure it was fresh and we use feeders with bee guards. We've had some trouble in the past with ants getting inside the feeders so we now hang the feeders on water-filled ant traps.
After a summer of having many hummers every day, we noticed a little over a week ago that they have all disappeared. It happened almost overnight. We've kept the sugar water fresh, but they haven't returned. Am I correct in assuming that they have likely migrated for the winter? Interesting how they all left at exactly the same time.