I have only been a duck owner since August. I began with 3 call ducklings, then someone gave me 2 older cayugas, I bought another call right after that then the person who I got the cayugas also gave me a runner. It wasn't until I got this runner a few days ago that I started noticing a behavior from all of them that I'd think would have a reason: flapping their wings really fast for 10 seconds or more. Is it a mating thing or something? It's odd that I didn't notice it until the runner got here. The previous owner had to let him go because he was chasing the female chickens and trying to mate with them. My ducks aren't with the chickens all day, only at night in the barn so I haven't seen him act that way. He doesn't even bother the female ducks! Any ideas?