Here are some of the lessons that staff have learnt - the hard way - in schools around the world over the past 12 months:

1. Don’t drink on a school night.

Teachers tempted to stay out late on a weekday should bear in mind the experience of a teacher in Kenya who, after one particularly wild night out, mistook his school for his house. When he woke up on the couch, he shouted at colleagues for invading his bedroom, before wandering out into the corridor to urinate against a wall in front of a group of baffled pupils.

2. Treat pupils’ gifts with caution.

Five pupils at Sequoya Middle School on Long Island, New York, stuffed doughnuts with chocolate-flavoured laxatives and gave them to 19 other students. It was only when a health teacher took a bite that the prank was uncovered and police were called to arrest the pranksters.

3. Don’t allow birthday surprises during lessons.

A teacher at Arnold Hill School and Technology College in Nottingham kindly allowed a parent to book a gorilla-gram for her 16-year-old son’s birthday and even agreed to video the boy’s surprise. Unfortunately, a booking error meant that a stripper arrived during the lesson instead. The teacher only intervened after the visitor had stripped down to her underwear, spanked the boy and asked him to rub cream on her.

4. Check what pupils bring to show-and-tell.

One week you might get lucky and have a child who brings in the family’s life savings, as happened at a primary school in Croatia. Six year-old Mario Cvitak showed, told and then proceeded to give out the equivalent of pound;6,000 of his grandmother’s money, thinking the notes were pretty pictures. His teachers kindly gathered up the money and returned it all.

5. Don’t underestimate pupils’ stupidity.

Dozens of pupils filmed acts of misbehaviour, posted them on the internet, then seemed surprised when they got into trouble. A group of Swiss pupils were caught out because they handed out flyers in advance for their “happy slapping” attack, while some Bulgarian students who vandalised a school heater could not resist filming it and putting their names on the credits.

6. Approach teaching jobs in China with caution.

There are many good schools in China. But be careful you are not being posted to the one that has opened in a cave, or the one that can only be reached by a zip-line across a 200 metre canyon, or the school in Beijing where the joint pupil-teacher toilets have cubicles with no doors.

But then again, always pick China over Sudan.