Why do blue jays peck on your window?

Blue jays may peck on Windows as a way to defend their territory or to attract a mate. They see their reflection in the glass and perceive it as a rival bird, prompting them to peck to assert dominance. Additionally, they may be seeking food or trying to get your attention, as they are intelligent and curious birds. This behavior can be particularly common during breeding season when they are more protective and assertive.