I have had hummers in the past- not many, maybe 2 at a time. Over the last few years, I have seen only 1, or none. I have not changed anything- 2 feeders, 4:1 water:sugar. Placed in sight- next to a large tree for perching and protection. Are they not so common here? I used to have 40+ at a time in Arizona Shonto). Are there good years and bad years? Maybe the feeder is being blocked too much from view by the tree?