What is a grey heron thinking?
Cleared the pond of every fish by Tuesday. Returns each morning to check.
Herons hunt at first light, which is why the pond is empty and nobody saw anything. They stand motionless for long stretches and strike with a neck that unfolds far faster than it looks capable of.
The returning is the part people underestimate. A heron that has found a stocked pond adds it to a circuit and comes back, which is why netting or a pond with steep sides works and a one-off scare does not.
Try it on a real one
Three peeks a day, free. No account, nothing to install.