A couple of days ago, I watched two hen hummingbirds having an argument over the rights to the feeder. They flew at each other repeatedly, and knocked each other off the feeder many times. They did this for 15 minutes. They were oblivious to me, as I took photos of them. I stood about 18 inches from the feeder and shot many pictures. They knocked each other down into the wet grass once and lay there tussling and writhing with each other. Then, they flew up to the feeder and settled down and drank for a long time. Then repeated the performance! This was about 7:30 AM, and it was quite a cool morning. Here they are tanking up for the second go-round.