Research into the behaviour of domestic cats has spawned a worrying conclusion: underneath the cuddly exterior, purring contentedly in their owner’s lap, beats the heart of a cold-blooded killer, planning the most efficient method of eliminating its human subjugator.

It’s a bit like teaching an upper-school class. Teachers and pupils work together all year for the common good of exam success, but the quizzical looks aimed at the committed educators are not because the student is confused by the work. The would-be Johnny Knoxville is just trying to imagine which pornographic body will work best superimposed under sir’s balding head as the school leavers prepare their hilariously original subversion of the school on their last day of term.

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The ongoing trend of school leavers trashing the staff and building has made the date of that final day a closely guarded secret, revealed only to the few members of staff who can be trusted not to blurt it out to their Higher class. Instead of maximising crucial teaching time after the Easter break - Scotland’s exams start tomorrow - a game of cat and mouse between school leavers and school management teams ensues; the upper school surreptitiously plan “pranks” while the SMT springs an early release date on unsuspecting inmates to stop those tricks from playing out.

These remedial measures may have reduced incidents of low-level vandalism/high-level high jinks or maybe these incidents are simply not being reported to discourage future year groups. However, it does make the last day of school a furtive attempt to usher the young adults through the door, rather than something to be celebrated with shirt signings and selfies.

Beyond the practical joke

I’ve never been fond of practical jokes, so I might not be the best person to judge whether sardines hidden at the bottom of lockers, dirty nappies stashed in the ceiling or black boot polish smeared on seats are just good-natured pranks or nasty score-settling. But they do seem like the acts of supreme egotists. These jokers cannot appreciate the work that has been done for them, but also refuse to countenance the fact that the institution continues without them and so decide the buildings should be defaced as a permanent memorial to their edgy behaviour.

But future students shouldn’t have to work in classrooms where the whiteboard is unusable because last year’s leavers swapped whiteboard markers for the permanent variety or where the playing field is scarred with a phallic image carved there in weed killer. Other last-day practical jokes have permanently disfigured victims hit by flying eggs, while a school janitor was badly injured after slipping on steps smeared in Vaseline.

The desire to subvert authority for one day has a tradition stretching back to medieval towns when, for one day each year, the peasants would dress up in their masters’ clothes and rule for a day. But school pupils haven’t been subjected to tyranny; they’ve been helped to create their own future opportunities.

Long-term hospital patients don’t traditionally scratch penises on the cars of the health professionals who have cured them on the day they leave hospital, as society would be outraged. And yet, teachers who are unhappy about the end-of-term debacles are accused of being killjoys.

It doesn’t seem right.

Gordon Cairns is a teacher of English in Scotland