2 little birds in a nest

For the last few months a window has been opened in the hallway outside my flat, I noticed 2 birds flying around it allot and it was very annoying. Then bird poo built up on the ground and I wondered why until I finally looked up and noticed a nest, I was going to close the window but it was jammed so they are lucky it did because I didn't know there was a nest at the time.

I have pictures of the 2 bird parents on my Flickr account click HERE Enjoy.