I had a problem with birds sitting on my car pooping on it. I do not have a garage, only a carport. To stop this, I got a rubber snake--a Black Mamba. I figured they'd see the snake, realizing it's the deadliest snake in Africa, and take off. If I was a bird I sure wouldn't mess with it. And they are no longing loitering on my car. Alas, they're now hanging over my roof pooping on my air conditioner (which is in the back yard).