Ya, I've definitely considered that for the other chickens, but i'm having a really hard time figuring it out for the ducks. Most duck breeds don't fly well, (thats all of my ducks other then the 2 mallards) and a hut with odd sized door wouldn't work as ducks are bigger then Doodle and Smudge. I'm at a loss.
Then only way I could think of to keep them out of the food is to let them out at different times. The duck run is pretty rocky though, we put it in a bad location before I knew about rocks and ducks. So the ducks really prefer to be in the grass as much as possible.