WOW, great idea about the board! I was wondering what i could do to keep them out. they stick their heads in and throw water onto their back drives me crazySo far the only heated bowl that stopped working was the one I dropped on the patio [stone] and it cracked. I place a board over a section of my heated buckets to keep the ducks from climbing into them and my geese from splashing out all the water. lol they can still dunk their heads just can't bath in them.
I use this method of fermenting my flocks feed. What breed of ducks do you have? some breeds will lay all winter long with short breaks, then other like me who have Muscovy's have to wait till spring for eggs since they are seasonal layers. https://www.backyardchickens.com/a/no-strain-hot-water-easy-fermented-feed-method-w-video if you have a TSC close by they have the heated bowls for 12.99 and heated buckets starting at I believe 34.99