I tossed a rabbit out of the hutch(not literally, he was set down gently) because he was busy scooping all the feed out and throwing on the ground. He was fine with the ducks for about 5 days and then I went out to find clumps of feathers on the ground and I saw the rabbit attack a duck, kicking and punching. I went to get a cage and by the time I got back, the rabbit was chasing a different duck, jumped on its back and was biting it. So the renegade rabbit is now in a cage, set on the ground and he has been informed that he gets fed twice a day and he can eat it or throw it out of the cage, his choice, but he isn't getting any more. I couldn't do that when he was in the same cage as his littermates. He threw the food out and then they didn't get to eat. So, getting around to the point, it appears that ducks and rabbits loose together in the same pen is not such a great idea.