Are you too old?http://uk.youtube.com/watch?v=w1VUEJ895gw
How does the Mosquito system work?
Mosquito is essentially a sounder unit that emits a very high frequency modulated tone that is completely harmless even with long term use. The unit has been tested by NPL to ensure it complies with all relevant legislation.
I am not a teenager, will the Mosquito annoy me?
This is very unlikely and research has shown that the majority of people over the age of 25, have lost the ability to hear at this frequency range. It should be borne in mind, however, that the unit usually has the desired effect moving the crowds away within just a few minutes, at which time the unit can be turned off. So even if you are able to hear the noise to some degree, you would not have to put up with it for long.