Ahhh, so your ducks go outside in the winter where the pool is...I remember when I moved out here, one night under my bedroom window we heard quacking at 2am. I couldn't figure out what it was, but in the morning saw duck prints in the snow. They were crossing the road from my neighbors during the night. This was before I had chickens, you understand...
I called her up in the morning, and told her, their ducks were coming over to our house during the night & waking us up.
She said she had trouble corralling them into their duck house & were loose that night. Apparently, duck feet don't feel the cold
After that she made more of an effort to get them locked into their house at night...and yes, we are still friendly...
Ok, I'll think about ducks....