I have a pond at my house with goldfish in it, and a few of my neighbors do too. I have had 10 goldfish in my pond for about 5 years now and take them in every winter. This year I am down to 3 and my neighbors have lost fish too - gone with no trace. I know that it is not a **** because i have a fence set up around it, we believe that it is a bird. I have tried to cover it with screen, but still lost one. They are beautiful outside, but also easy pickin's for birds.