X10 on SSS.
Of course I don't think the city folk know what that is.
But seriously, throw a tennis ball in the air and shoot at it. Then do it again, then do it again, then do it again. Long after they are gone.
Then wait for them to return, And do it again.
Ain't nothing wrong with shooting a tennis ball.
After a few times they will relate those chickens to the pain in their ears and will GO AWAY. This works for Owls, Crows, Ravens. Eagles, all of them. The good part is, you will get good at hitting a moving target so when you are visited by a coon, mink or possum, you will roll em up like a dirty rug.
Ya Ya I know, its a FEDERAL crime to harass protected species. To hell with them, I'm SHOOTING AT A TENNIS BALL!!!