goldfinch looking at me

I have a load of bird feeders hanging outside my window. I can spend hours looking at the birds. There was a bit of a fracas going on between the goldfinches and a greenfinch. The goldfinches outnumbered the greenfinch and the greenfinch flew away. I was watching the events when one bird returned my gaze.
I am having trouble getting a good picture through the window. I think it would help if I cleaned it.