I went to the kind of small Scottish private girls' schools that only admitted or kept well-behaved girls, and as they employed teachers who loved teaching and understood children, school was FUN from the first day until the last one.
So there was no incentive to be naughty.
The worst thing we ever did, as a class, was to hang out of the windows overlooking the street calling to the boys from a boys' school going past. Our new headmistress, whom none of us liked, was NOT AMUSED, but did not know the class well enough to know, that the girl who piped up with, "Please, Miss, I was only giving my brother a message from Mother" was telling the exact truth, but that none of the rest of us had brothers amongst those boys, or indeed on my and many others' parts brothers at all!