A huge killer of birds? Windows. The animals don't realize they can't fly through the transparent panes because of a reflection on the glass. But one thing you may not realize is actually intensifying the false illusion are mirrors in your home. Walk around the perimeter of your home and see if any mirrors inside the home are reflecting the outdoors. If one is, consider moving the mirror or making a habit to close the door leading to the room to block the image entirely. It's one small step to help lessen the heartbreaking moments when you find a dead bird outside your home.