What do you do when your bridge is covered with starling droppings (Sturnus vulgaris)? When all else fails, bring in the cannons. At least that's what they're resorting to on I-5 in Seattle, Washington, according to this article in The Seattle Times. The cannons fire loud propane blasts rather than releasing projectiles. Officials are hoping the booms will be enough to scare away the starlings, which roost in far greater numbers than the pigeons that flocked to the bridge in past years.