When I was in NY for sukkot my daughter and son went into my parents bathroom and took the nail polish and smeared it all over the floor with their feet, they put it in the toilet and on the sink counters. They both made a major mess.
another story
My 2 year old son went into the bathroom with out me knowing and took the toilet water and took a bath with it. The most discusting thing about that is he used the water right after my daughter used the bathroom with out flushing