You may never see a raccoon during the day. They are generally night hunters and well adapted to fishing in the wild. The domestic cat normally isn't as much of a threat though still worth a warning. A sick fish swims slowly and near the surface. This gives the cat an advantage.
Fish swim slower during the colder months giving any predator a better chance.
These are only a few of the predators that prey on pond fish. They are the most common and, by studying their behavior, we can better protect our fish from all. The Heron is a pretty tall fellow. If you see him, you can't miss him. He's a crane with long legs built for wading in shallow water and has a long beak perfect for spearing fish.