How normal is it for birds to repeatedly fly into a window? These little stupid gray and yellow birds fly into the window at full speed and scare the crap out of you; it sounds like a golf ball hitting the window. Sometimes they even knock themselves silly doing this. But that doesn't stop them.
All week long a cardinal has been attacking the windows. He hovers near the window and pecks at it and generally goes nuts. The windows are tinted, so maybe he sees his reflection and thinks he's attacking another bird?