I used to have muskrats that controlled cattails to a certain degree along with controlling my spatterdock, and they kept their digging to the far side of the pond so that made them exceptable for what I wanted. But when I got a dog they disappeared so maybe the dog had something to do with it, I don't know. I used to watch the muskrats to see what they ate or were doing. It's crazy. They were swimming from the far side of the pond to another part of the pond, then going up on land and pulling and bundling my long bison grass, then swimming with these big bundle in their mouths back to their dens. Perhaps they were lining their dens with it for beds or maybe eating it. Interesting. My English Springer Spaniel patrols the shore for anything that moves so maybe a hunter dog is the answer.