I don't know why this never occurred to me before. I was out hosing out the duck pond earlier and noticed that the ducks were crowding in and trying to catch the spray. It has been a while since it rained much. So, when I was done, I put out a little sprinkler and turned it on. Next thing you know, I had almost 60 ducks all crowded into an 8' radius around that sprinkler. I just left it running and they are all out there playing in the mud, having a good old time.