How can you poison wild chickens, so they'll stop destroying your yard?

I used to have a nice yard, with flowers and vegetable seedlings. Now, when I come home from being at work all day, I have huge holes in the ground where my plants used to be. On my days off, early in the morning, they scream right outside my window and wake me up. When I chase them away, they come right back and scream again.I can have NOTHING nice any more, and not enough sleep. I want them DEAD.