As birds fly home for spring, you would think everyone is excited for their return. This year, however, the birds return carrying the bird flu with them. This dangerous disease can weaken and kill many. If you don't want your city to be overrun by bird flu, you have to keep the birds away from your city. Birds fly from the left side of the screen to the right side, where your city is. Click on them to shoot them before they get to your city and infect your people! To aim, use your mouse to aim. Click to shoot. Push the space bar to pause the game and buy more ammo.