Just that really: are teenagers (or children generally) just nastier at this particular point in the Christmas term? Is it the clocks going back and more darkness or more tiredness or work/approaching public exams catching up with people and making them ratty?
Both my two: Y11 and Y13, have come back with tales of unpleasant behaviour on the buses, in classrooms. Girls bitching about other girls in front of them and behind their backs. Boys being bullies on school buses.