A few weeks ago we found that many of water lily leaves got some damage in the pond. I wondered it could be happened by our mischievous Koi fish or nasty bugs. I called my dear gardener to have a look at it,
and he said they were poked by some big birds such as Sagi, herons. I knew, especially in winter time, herons often visited our garden, looked into the pond and made a hunting pose to our Koi fish which could be too big for them to pick up.