VERY IMPORTANT a dam in the Netherlands, the weerdsluis lock, is directly on a migratory path for spawning fish. They have a worker stationed there to open the door for the fish, but they can take a while to open it. So to keep the fish from getting preyed on by birds they installed a doorbell. Only, the fish don't have hands to ring the doorbell. If you go to their website, they have a LIVE CAMERA AND A DOORBELL that YOU RING FOR THE FISH when they're waiting, and then the dam worker opens the door for them! I can't express how obsessed I am with this. look at this shit. oh my god.

Please check on the fish doorbell once in a while :)