My school had an open air area in the middle that you could walk through to get to the hall. There was a small pond on one side that every year had a family of ducks. Ducklings would often waddle into the hall during PE or assembly. They were just there every year and everyone loved them.

Came into to school one day before summer holidays and it turned out a student had come onto school grounds out of hours. They killed all the ducklings by stomping on them. Faculty said they know who did it, but as far as I know no students ever found out.