Out of the Blue (opens in new tab)

I've been checking on the robin's nest outside our kitchen window pretty obsessively since it was constructed. As time passed my concern grew that for some reason this would remain unoccupied. My online research suggested this was possible, but I'm smart enough to know that I'm dumb enough to be subject to the Dunning-Kruger effect, even with my newfound internet expertise. After realizing there should be a way to see into the nest from upstairs, and sure enough there's an angle where this is...