We have a robin that has been flying at one of our windows for the past few days. Almost every minute, there's a soft "thunk" as the bird hits the glass and then stares at it, almost looking in.
I found out this is a mating/protection pattern in that the robin sees its reflection as an adversary, and it'll stop once it finds a mate.
I'll let you know when I finally notice the absence of the "thunk". 😅




is ridicously