JUST FREAKIN' LEAVE!!!

We haven't been able to use our backyard for several weeks now. There is a nest under our deck and Mommy and Daddy bird are very protective. So now there is one bird left in the nest, too lazy to move out, even though all his brothers and sisters have flown off. I have been trying to find ways of making it leave. Our window downstairs opens right up to a great view of the nest. So far I've managed to miss the bird with the rubber band gun, and my rock aiming is terrible. I got it pretty soaked with vinegar water, but it didn't seem to care. I'm going to go try a paper airplane now, but I'm running out of ideas.