Since the dawn of time, children have found ways to outsmart adults. Now, technology is making it too easy.

Last year “the mosquito”, a device that emits a high frequency tone unable to be heard by adult ears, was heralded as being “teen repellant”. It was used outside Welsh convenience stores to stop teenagers from loitering in front of the entrances. The Wyvern Theatre in Swindon also used the mosquito to deter groups of teens from congregating nearby.

But, teens have now employed their technological savvy to use the tone in their favor. Students across the globe are downloading the tones onto their cell phones. Because most people over the age of 25 cannot hear the tone, students can receive text-messages and voice mail in class without their teachers having a clue.

To hear a clip of the annoying tone, click here.