Rowdies buzz off as the Mosquito bites

THOUGH he did not know it at the time, the idea came to Howard Stapleton when he was 12 and visiting a London factory with his father.

He could not bear the noise from high-frequency welding equipment, but the workers didn't hear a thing.

Now 39, Mr Stapleton has taken the lesson he learned that day — that children can hear sounds at higher frequencies than adults can — to make a device that he hopes will solve the problem of obstreperous teenagers who hang around outside shops and cause trouble.

The device, called the Mosquito ("It's small and annoying," Mr Stapleton said), emits a high-frequency pulsing sound that he claims 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.

So far, the Mosquito has been road-tested in only one place, at the entrance to a convenience store in the town of Barry, South Wales. Surly teenagers used to plant themselves just outside the door, smoking, drinking, swearing at customers and making disruptive forays inside.

Robert Gough, who owns the store with his parents, said the youths would sometimes fight, steal and assault staff. Last month, Mr Stapleton gave him a Mosquito for a free trial. The results were almost instant. It was as if someone had used anti-teenager spray around the entrance. Where youths used to congregate, now there is no one.

At first, members of the usual crowd repeatedly went inside the store with their fingers in their ears and "begging me to turn it off", Mr Gough said. But he held firm and avoided possible confrontations: "I told them it was to keep birds away because of the bird flu epidemic."

Mr Stapleton, a security consultant, used his children as guinea pigs, trying different noise and frequency levels before settling on a pulsating tone he said was more unbearable, and which can be broadcast at 75 decibels, within government safety limits.

"I didn't want to make it hurt. It just has to nag at them," he said.

"It's very difficult to shoplift when you have your fingers in your ears."

NEW YORK TIMES