We have one of these crazy cardinals also. If he's not banging his head into the office window at least 20 times in a row, he goes to the dining room window, to my husbands work shop, or down to the shed where the tractor trailer and tractors are stored. In the house I can lower the blinds, but then I don't get the sunlight and after being in the house so long after the winter I miss the warmth of the sunlight. Personally I think this bird has a mental problem!! I call him "Crazy Bird".