My neighbors have a mirror propped up against their house. This male cardinal lived in my backyard area and was fascinated with the mirror. Male cardinals are known to attack their own reflections, thinking it's another bird. He would go to the mirror every morning, look at himself, and then try to attack it. When I would walk over, he could see my reflection, and then become confused. He started looking behind and around the mirror, but never quite figured it out. He sure was cute though!