We are a retreat centre with attached permaculture gardens in south-west Turkey and have a medium-sized pond and a smaller natural pool (for humans only) about 200m apart. When people are in or hanging out by the pool, the ducks stay away. But when it is quiet, the ducks find their way there… so I gave the ducks to a friend. In our experience, retreat guests don’t want to share their swimming space with largish animals that poop! (We don’t mind!) Any suggestions other than re-educating our guests?