Geese !!

[Smith Point]

I like the string idea also, but I use old fishing line. (you should probably replace it anyway) with a little different application, wherever the geese enter your property just put four small stakes in the ground at goose height, in a zigzag pattern and wrap them with fishing line. When they trip over it they will squawk and flap their wings and never come back. Worked grate at the little lake house.