Hi everyone,
I read about Adachi ward, in Tokyo, continuing the use of the Mosquito.
The Mosquito is a device that emits a high frequency, which can be heard by teenagers and young adults.
This is being used to prevent vandalism and loitering in public areas at night.
It seems to be working.
I never realized that teenagers, people in their early twenties, and dogs, had similar hearing.

(洋書で英語)モリー先生との火曜日 Tuesdays with Morrie: An Old Man, a Young Man and Life's Greatest Lesson