😬 I love ducks but I sure as heck do not want anyone else's ducks but mine on my property. They poop everywhere and root around and can make a quick disaster of gardens.
Just remember, just because you wouldn't mind someone else's animal on your property doesn't mean your neighbors complaints...
Realistically a fence is the only thing that will work. You might be able to get away with just fencing off the section where they typically get over into the other neighbors area.