I have no idea what a duck nest box is supposed to look like. Are they just like chicken nest boxes? Do ducks like them covered and dark? How big should they be? (I have one swedish, 2 calls, 1 runner, 3 ?'s If I have the ducks on a pond is there a way to build them a nest that is somewhat predator proof? Will it work if I put the ducks up at night and let them out in the mornin on pond?