First time ever, I witnessed a female hummer sipping quietly at the feeder and a male hummer came diving towards her in a pendulum style "U" shape - back and forth above her, maybe 5 or 6 times, almost hitting her while she was feeding and making a very strange chirping sound. Guess he was doing a mating dance of sorts, she didn't seem to impresses as she flew off in the other direction! lol
We have 4 feeders around the property. This one is at the back kitchen window and it motivates me to scrub some dishes as I have some entertainment in the process.