Howard Stapleton (Merthyr Tydfil, Wales) invented an electromechanical teenager repellant -- a device that makes annoying high-pitched noise designed to be audible to teenagers but not to adults. The "Mosquito" ultrasonic teenage deterrent aims to solve the problem of unwanted gatherings of youths and teenagers in shopping malls, around shops and anywhere else they are causing problems, claiming to be "the most effective tool in our fight against anti social behaviour". He later used that same technology to make telephone ringtones that are audible to teenagers but probably not to their teachers.More
