So the last couple of weeks I've had a little friend come and visit me at my office. He seems very intent on getting inside. Though there are several theories that we can look at as to why this behavior occurs.
Territorial Behavior - The bird may be attacking what it perceives as a threat to it's territory. That being the reflection of the bird itself in the window.
A returning spirit - Many people believe that birds who come to a window are the spirits of the dead come back to visit. A few of us in the office have lost loves ones lately, so I suppose this bird could be any number of lost loves ones who have come to see us.
Brain Damage - The bird could just be dumb and taking on brain damage every time it bangs it's head into one of the windows it flies up to.
Who knows, who can tell. Maybe you can have some theories in the comments.
My video is at DLive