Are they very territorial? We have a feeder and watch one particular hummingbird that just stays in a tree nearby and if any other hummingbird comes near the feeder, he dashes down and chases them away. I call him "Johnny On The Spot". He is there so quickly nobody else can get a drink. He lets me know when the feeder is empty by coming to me and just hovering around 4 feet from my face, little bugger!