Campaigners want to ban ultra - sonic device used against young people . ` The company says The Mosquito has proved popular with shop keepers who buy it to move along gatherings of teenagers and anti-social youths . ` The Mosquito '' emits sharp sounds that can only be heard by under 18 . About half of the devices are used in England to disperse young people . Human rights groups say they create divide between young and old .
Campaigners want to ban ultra - sonic device used against young people . ` ` The Mosquito '' emits sharp sounds that can only be heard by under 18 . About half of the devices are used in England to disperse young people . Human rights groups say they create divide between young and old .