Gangs of youths who terrorise shopkeepers and their customers in a Staffordshire town are being targeted with a device which transmits a piercing, high-pitched noise which sends them running for cover.
The Mosquito, which has been installed in a shop in Leek, sends out a noise which can only be heard by teenagers and those in their early 20s.
The three-week pilot project has seen a dramatic reduction in youths gathering around the shops, according to the local police inspector.
The Mosquito has now been re-located to another area which has problems with gangs of youths. The device can usually only be heard by younger people whose hearing is more acute, and has a range of 20 to 30 yards.
The company which develops the Sonic Teenage Deterrent said interest in its product had increased massively in recent months. The device is currently positioned in a number of locations around the Midlands.
Staffordshire Police Inspector Amanda Davies said the device was installed on a shopfront in Leek following complaints from local retailers who said youths were congregating outside their stores and intimidating customers.
Insp Davies said: "We needed a simple and effective way of dealing with gangs of youths which does not need police officers having to go out and take names.
"The youths will not stand around the device for very long. They just want it to stop.
"Last weekend a group of youths went into a shop and asked the owner to turn it off because it was that uncomfortable for them.
"We have had people throw things at the device, but it is protected by a large cage."
Insp Davies, who is also the community safety manager at the local policing unit, said a local youth club set up near the Mosquito had seen an increase in youngsters attending in recent weeks.
"We do not just want to move them into another area. There has to be some diversionary activities for young people," she added.
"I would stress that this device doesn't cause any pain to the hearer and has been vetted for any health and safety implications.
"It is not on all the time and i t is controlled by the shopkeepers.
"If they can see through their window that there is a problem, they turn the device on for a few minutes until the group has dispersed."
The device, which costs £622, was invented by Howard Stapleton, the managing director of Merthyr Tydfilbased Compound Security Systems.
It is being sold to police forces, local authorities and the retail sector. The company is currently in talks with retailers Spar and Co-op.
Plans are also being drawn up to market the product to private individuals who are fed up with gangs of youths congregating on their doorsteps, a spokesman for the company said.
"At the moment trade in the Mosquito is going amazingly well," he said.
"We have had cases where youths have tried to vandalise them but they are protected by a very strong security cage.
"The youths have come up with remarkable ways of trying to wreck the devices, but none have been destroyed so far."