Please let us know if they come back.I, too, lost ducks one at a time with no trace. Had to be flying predator. I don't live where my ducks do so was not there to see it. Area is known to have a fox. This year I built a floating duck house and my new four ducks were safe for at least six months. First week in December they flew off. I am hoping they will return next spring. The floating house kept this little flock safe.