Anti-social behaviour in schools

Someone on the staff keeps going into the toilet and dropping an enormous log into the pan and then not flushing it away. Despite the fact that this is almost a daily occurence, it always takes you by surprise. They don't even look like a human has done them...

It also makes life a little awkward. If you're in the cubicle and there's someone waiting to go in after you, you can hardly say, "Oh that's not mine, by the way.".

How are we to teach the youth of today responsibility when teachers can't even take responsibility for the contents of their own bowels, I'd like to know?