Chickens can hatch and raise ducklings. And they can be housed together..... But there is different watering requirements and ducks can tend to be alot messier than chickens...But it is possible.
I know people who hatch out ducklings under broody silkies and cochins...
Oh and my ducks always lived with my chickens when i was a kid, so it's definitely an ok setup. Just use 1 gallon milk jugs with a hole big enough for a chicken or duck head in the house and have a pool outside. Always leave a cinder block or something in it to allow a chicken to climb out just in case.
Way cool. I think I will have to try this when one of my Cochins go broody. Right now I have 2 wild ducks in our swamp/pond. I would like tame ones there.