Used HN in week two with chicks, they picked it up with no issues what so ever. Tapped the nipple they came flying over and took it from there. Love this system.
05/15 - used this with five day old chicks and they picked it up right away.
06/04/15 - introduced waterer to chickens hatched by a broody Cornish. The chicks were introduced on day 2 and on day 3 I saw them actually using it. Good job mom for teaching them so young. We do not heat the chick waterers as we don't have chicks In the winter.
I think ducks can learn to use it. I have been putting my bunny in the pen with the ducks and chicks and I have seen the ducks go up to the bunny's water bottle and start using it. I'm making a bucket with chicken nipples like in the picture above (thanks for the great pics and inspiration) because it will keep the water cleaner. I will let you know how it works out!!!