All day today I have had a Brown Thrasher who comes and sits on top of a shephard's hook where the bird feeder hangs and continually flies into the window facing him. He flutters a few seconds into the window, then returns to his spot and repeats. I have shooed him away for fear of him injuring himself, only for him to return. I hung up a towel over the window, thinking he was reacting to his reflection, only for him to fly to the window pane above it and repeat the behavior. Does anyone have any ideas as to what's going on or has anyone seen this before?