I dont know a ton, but I know they are very territorial, Usually when you have more than one they are fighting and trying to run the other one off from the feeder. While we were in blue ridge a month or so ago, they swarm like bees at my friends cabin, she has feeders everywhere, two were fighting and they hit the kitchen window while I was washing something and one of the birds got its little beak stuck in the screen..... I was like oh no, and it took it a second but it got out, then I laughed all day, it was one of the funniest things Id seen