My daughter would really love a few ducks for her birthday. We currently have 12 chickens. The ducks would share the same back yard but would have their own coop. I am looking for a breed that: 1)is quiet 2)can't fly 3)is calm 4)is a decent layer. Now, beyond figuring out the breed, are there care requirements other than providing a pool for them to play in (and keeping that water fresh) that is different from chickens? Thanks for the help!