So, maybe there is at least one advantage to getting older and losing part of your faculties. There is a hallway in Lafayette Jefferson High School in which administrators don't want the kids to congregate. So they installed something called a Mosquito, which emits a high-frequency noise:
Billed on the company's website as “the most effective tool in our fight against anti social behaviour”, the Mosquito is designed to be annoying for people under the age of 25, but largely inaudible to older adults who lose the ability to hear high frequencies.
Wow. Annoying to those under 25, but I can't hear it. Maybe I could have one installed in my yard, sort of a reverse invisible fence of the type meant to keep dogs in. Sure would beat having to yell, "Stay off the lawn!" 10 times a day.
This just in: Business owners in a plaza in New Zealand have taken to playing Barry Manilow music over the loudspeakers to take advantage of the technique "that has been used worldwide as a way to make places unattractive to youths."