Stores and shopkeepers in England use high frequency devices used to deter mosquitos and children.
The high frequency sonic devices can only be heard by the sensitive ears of children rather than adults. Since the noise is annoying, children tend to stay away from areas. Some concerned citizens and activists are lobbying to ban such devices. While the devices may be effective in reducing loitering, the devices do not solve the true problem which is providing meaningful and interesting activities to children when they are not in school. You can read more about this issue at the Florida Times Union Web Site at British campaigners call for ban on ‘mosquito’ devices used to drive children away from shops.