The Adachi Ward Office in Tokyo has  found a interesting way to keep youths away from the park at night. They use something called the “Mosquito” a device that emits high- frequency sounds that can only be heard by teenagers and people in there early 20’s.

The reason that the Ward office is trying to keep youth away from the park is because of  late night loitering , and destruction of property by teenagers. The Mosquito was put on a trial test, but when the trial test ended in April, the Ward office decided to continue useing the Mosquito because of its success.

“Thanks to a combination of the device and night patrols, vandals and loiterers have almost disappeared,” a ward official said at a meeting of the budget committee of the ward assembly on Friday. “There have also been no reports of health hazards (from the device).”

The device had been put into operation late at night, but the ward is planning to activate it only if similar problems occur again in the future.

The ward will compile guidelines for the continuous use of the device later this month and consider the installation of more units.

The Mosquito was released in 2005. When Adachi Ward introduced the device, it received media coverage from home and abroad.

I wonder if the people participating in late night patrols are over 20?

Source