Strike hard, strike fast, and strike frequently BEFORE you have a problem on your hands. In other words get rid of those few geese NOW.
Some have success with flashing red lights (think airport lights), others have success with fireworks (shooting roman candles you guess where and bottle rockets), and even remote controlled cars, boats and helicopters all may be used to annoy the peacefulness and therein cause unwanted inhabitants to leave.
You have to be vigilant and get them gone. They are a nightmare.
