Herding Ducks

I have been noticing a pair of wild Mallard ducks have been visiting the pond the past week.  I see them every other day.   My corgi was at the farm with me today and corgi's are herding dogs, so she decided she was going to herd the ducks, which means running around the pond and barking at them as they moved from one side of the pond to the other.     Its nice to see wildlife on the pond, but I don't want them to decide to nest in the area.   They will come back to the pond with their babies and the catfish in the pond are very big and will eat the babies with one bite.   I don't want to see that happen even though its mother nature at work, so I have been chasing them off when I am there.