This is the kind of brilliant idea that should make its inventor a millionaire: a high-frequency buzzing device that drives away teenagers but is inaudible to most adults.
The device, called the Mosquito ("It's small and annoying," Stapleton said), emits a high-frequency pulsing sound that, he said, can be heard by most people younger than 20 and almost no one older than 30. The sound is designed to so irritate young people that after several minutes, they cannot stand it and go away. ...
A trip to Spar here in Barry confirmed the strange truth of the phenomenon. The Mosquito is positioned just outside the door. Although this reporter could not hear anything, being too old, several young people attested to the fact that yes, there was a noise, and yes, it was extremely annoying.
"It's loud and squeaky and it just goes through you," said Jodie Evans, 15, who was shopping at the store even though she was supposed to be in school. "It gets inside you."
I must be getting old to love this idea so much.