We put feeder fish in the wading pool with our ducks today. We have three pekins and three mallards. We have had them for almost three weeks. They were small ducklings when we got them, and I am not sure of their actual age. At first they did not notice the fish. The first one to pay any attention was a mallard named Trouble. His name fits to a tee. He darted and dived until he got one. As he was working to get one, the others started to catch on. It was extremely funning when they were all going after the fish at the same time. I think the fish will be a once to twice a week treat for them.