My first and oldest koi has disappeared assuming by a predator. Rocks surrounding the pond would shift if something entered from the pond edge therefore I'm assuming it was a hawk. The koi was large and bright orange. I also have 4 new kois of smaller size and now no longer see them. I don't believe a hawk could have caught them because of size and not being very active as yet in the pond. Does anyone know if snakes would enter the pond to scavage my kois?. I know there have been snakes seen around the pond in the past but have not seen any recently. My pond is 4-5 feet deep with lots of ledges for the fish to hide.