This pair of blue birds have been knocking on my door every day. It's amazing how intelligent these little guys are. Some times they pick up a corn kernel and throw it or spit it at the window. I put a window feeder up so they can rest after all the carrying on. Closing the blinds dosen't help. They can get very angry. Wonder what would happen if I open the door and let them in. See some of my pics. They are very close up! hummm