The school plague: pupils release 4,000 hopping crickets into end-of-term buffet

More than 4,000 of the insects were released into the sixth-form common room at Exeter School, where a parents' buffet was being held.

Amid chaotic scenes, staff at the £3,000-per-term school had to seal off the building and call in pest controllers.

Scroll down for more

Now headmaster Bob Griffin has warned pupils that the parents of the culprits could be asked to contribute to the £1,000-plus cost of the clean-up.

The pupils had bought the insects from commercial breeders for £12 per box of 1,000. They are bred as lizard food.

One sixth-former said: "It was mayhem in the common room, with crickets hopping and caretakers stamping everywhere. A massive cheer went up – all the senior staff wore fixed smiles.

"After the mass release those responsible sent triumphal text messages to fellow leavers who had headed for a local pub to celebrate their last full day before A-levels started.

"Some of us felt it was a bit over the top. But the school does pride itself on producing creative pupils.

"The head is still interviewing suspects. They are being told that their parents may be billed for cleaning costs. But no one has been accused, or excluded, because he can't prove anything.

"If they try to bill parents, it won't go down well."

The pupil said a number of small-scale practical jokes had been carried out in the run-up to the cricket caper.

These included sixth-formers using their cars to occupy staff parking spaces and spraying "Leavers 2007" on the playing field in weedkiller.

"We were just fulfilling a school tradition," he insisted. "There are always practical jokes on the last full day before exams.

"Two years ago two guys dressed up as chickens, invaded the final assembly and posted their efforts on the internet."

"Last year's leavers were a bit lame and just chucked some benches in the swimming pool. A few dressed up as superheroes to water-bomb people.

"This year we were determined to raise the bar, especially as the headmaster is a bit of a disciplinarian and doesn't like pranks. Everyone saw that attitude as a challenge."

Founded in 1663, the school – motto Take Fast Hold Of Instruction Let Her Not Go For She Is Thy Life – has 670 pupils of whom about 100 are currently taking A-levels.

According to its website, pupils develop values of "honesty, self-discipline, commitment and self-motivation" within "a Christian framework". The school also offers "an adult atmosphere in the sixth form, in which pupils enjoy greater freedom and are allowed more independence.

"In turn they are expected to set high standards both in work and areas of responsibility".

Richard Jones, owner of Exeter-based Pest Control Services, confirmed that he had been hired.

He said: "I cannot discuss the nature of their problem. If you're asking about crickets generally, it's fair to say they used to be commonplace in boiler houses, hospitals and even nuclear power stations.

"These days modern insecticides keep them under control."

Mr Griffin refused to comment.