Mosquito

This is a new meaning for the Word "mosquito."
Mosquito (plural Mosquitoes or Mosquitos) noun [countable]        

An electronic device that produces a high-pitched sound which can only be heard by children and younger adults, used as a way of discouraging young people from loitering in particular locations:

'As many as 3,500 Mosquitoes are estimated to be in operation across the UK to disperse children and teenagers in public areas such as parks and shopping centres …'
The Edinburgh Journal 26th February 2008

 

The Mosquito is an electronic device which emits loud, high-frequency sounds, so-named because the sounds resemble those of a buzzing insect. Because the ability to hear high-frequency sounds deteriorates as people grow older (a phenomenon technically known as presbycusis), the ultra-sonic tones produced by the Mosquito are most likely to be heard by children, teenagers and younger adults, generally anyone under the age of 25. When the Mosquito is turned on, older adults will usually only hear a faint buzz, but younger people and children should hear a very annoying noise.

 

In an effort to combat the anti-social behaviour associated with groups of youths in public places, over the last couple of years many shopkeepers across the UK have chosen to install the Mosquito outside their premises. Gangs of teenagers congregating and hanging about in shop entrance ways and other public places can sometimes cause serious problems, from intimidation of staff and customers through to actual physical assault. Many retailers who have installed the Mosquito device are reporting a dramatic reduction in such problems as a result.

 

Source: Macmillan Buzzword