This video from North Carolina in the USA says about itself:
11 October 2015
Dark Eyed Junco Kew Kew Kew calls. Delightful and energetic forest sparrows with pitch black eyes and a white beak and tail feathers, Dark Eyed Juncos are fun birds to have around. Depending on the light they can look gray or quite blue and striking. Not ones to share a food source the two Juncos in this video chase each other around.
From the NestWatch eNewsletter in the USA, May 2016:
NestWatcher Finds First Dark-eyed Junco Nesting in a Birdhouse
When Melissa Sherwood wrote to NestWatch asking if it was unusual for a Dark-eyed Junco to nest in a birdhouse, we initially thought it was a case of mistaken ID. We told her that juncos don’t nest in cavities, as they are known to be open-cup nesters (although they will nest in crevices or crannies near the ground).
As you may have guessed, she was vindicated. When she submitted the photographic evidence from her Washington home, we couldn’t believe our eyes. Never say never, even when it comes to a very common species.
We searched the NestWatch database to see if anyone else had ever reported this phenomenon, and found an instance of a junco nesting in an open-fronted nest box (the kind designed for Carolina Wrens). We found no other instances in the literature, nor in the historic nest record cards that pre-date our NestWatch project. As far as we know, this is the first instance of Dark-eyed Juncos nesting in an enclosed birdhouse.
Interestingly, our search of the scientific literature revealed two historical mentions of Dark-eyed Juncos nesting in old woodpecker holes, but both sources were over 100 years old! If cavity nesting is a small and rarely-observed part of their nesting repertoire, that makes Melissa Sherwood the first person in over a century to witness it!