As it turned out later, my neighbor had already been watching everything perfectly from her window for several evenings.
She had seen the teenagers gather at the entrance, swear loudly, throw garbage, and behave as if the yard belonged only to them. Her patience had run out.
It turned out that in her storage room she still had some old toys from her grandchildren — rubber “poppers” that, when dropped, make a loud bang and a strange metallic rumble.

That evening she secretly tossed a couple of them right under the bench, a little to the side of the teenagers.
The characteristic crack, the bangs, and the unexpected vibration did the trick: the effect was so convincing that the boys truly believed in a “mysterious force of the yard” and bolted away as fast as they could.

Later the neighbor confessed with laughter: “Let them learn the cost of noise. If they want to shout — let them do it somewhere else.” I could only shrug.
Sometimes the simplest “grandmother’s lesson” turns out to be far more effective than any sermon.