We had a male Cardinal that constantly pecked our windows...called him Peckerhead...pretty original eh?! Haven't seen 'im around this year...darn
Cardinals are well known for this attitude. Put a mirror out and they will be worse than at a window. They want to destroy that other bird they see and just keep on coming back. Yes....bird brain it is.
I didn't know this.... I had one that used to perch on the belt molding and peck at the outside rearview mirror on my work vehicle.
The same Cardinal that pecked the house windows did the same thing on my truck...pooped ALL OVER the window/door/mirror in the process. Had to scrub the heck out of it to get it off. Some cheap dollar store rubber snakes on the house window sills kept him at bay for a while...until he figured out that he could peck the window up high...not get too close
As I was enjoying the sun rise from the screen porch this morning, I heard a wood pecker tapping out a signal on the neighbors tin storage shed! Guess what thread I thought of right away?