These ducks are ruens and snowy mallards. And I guarantee they eat fish. I was putting more riprap on the pond and I watched them take out one of my sunfish as well as a couple frogs. One nearly choked on the frog. I think it is time to start giving them lead poisoning one by one so its not to obvious. My daughter is on to my resentment of the ducks and has been getting home from school and counting them. You should have seen her face when she came home two nights ago and I was grilling chicken breast. she almost shot first and asked second.....