we have 3 great pyrenees with our flocks and they are FANTASTIC dogs. I always warn people that it takes YOU training them and working with them until age 3 to get them to be fantastic. Our "puppy" is 1 now and is not permitted loose with the ducks yet, but is permitted to be tethered to the 3 year old boy for guidance when we cant be with him. He is great with the goats and ignores the geese as they move about. The ducks still peak his interest though lol. In another years time he will be fine as well. Our 2 three year olds are wonderful, and wont allow anything 2 or four legged to get inside the fences.