Meet my neighbors

These two guys regularly park themselves on the railing outside my office window. They are quite happy to sit there, preening and chirping away.

Occasionally, they get riled up and start flying into my office window. They see their reflection in the mirrored glass and start 'fighting'. They then sit back down on the railing - looking like they have just been smacked upside the head and wonder why the bird they are fighting is so damn tough.

B.