Signs from the birds

This is the window at the top of our stairs, looking out to the street. Ever since we moved in, there has been this annoying Cardinal that always flies into this window and the window around the corner on the other side of the stairs. We have kinda grown used to it, even though I would still like the bird to disappear. My sister jokes that if my windows weren't so clean, the bird wouldn't fly into it...... Well Hollie, they aren't clean... and check this out.


As I was walking by this morning I noticed something kinda creepy.

Upon further investigation, I realized it was a very eerie smily face, left by the birds..... or at least I hope it was by the birds. I'm a little freaked out by it.