'Once upon a midnight dreary, while I pondered, weak and weary, Over many a quaint and curious volume of forgotten lore― While I nodded, nearly napping, suddenly there came a tapping, As of some one gently rapping, rapping at my chamber door― "'Tis some visitor," I muttered, "tapping at my chamber door― Only this and nothing more." '

I'm kidding. If the window is clean enough there could be a little bit of a reflection.Its possible that the bird is just exploring though. I've seen raven actually sit by windows at my school in Cedar City. They'd tap on the glass too.

He wants in, let him in and give him some bird seeds.

It was during noon when a little brown bird (which i suspect is a sparrow), came knocking on my bathroom window. At first I thought that it could be just a natural phenomena of birds stuff as I have read elsewhere that birds do peak at their own reflections sometimes especially during spring time (which is now), but then I've just realize that the bathroom window is made of frosted glass so there should not be any reflections there (or are there?) . My mom told me that the bird peak at a room she was in during the morning too but that was juz a normal glass probably due to its reflection. Could some1 please clarify this for me? Thanks a bunch in advance.