Attack Of the Bird - The Window Won

In the 22 years of living in this house, we had a new experience that I have never had before. 

We have had about 10 birds over the years fly into the windows just after I wash them. I was sitting in the basement mid day and I noticed a bird standing on the ground watching me through the basement window. It kept hopping back and forth watching me. 

Princess Five said that this morning early, it flew into the big window once and then was sitting on the brick just outside the windows pecking and attacking the window. I thought she was exaggerating as I couldn't imagine a bird attacking a window. 

When I got upstairs a bit later. I found several books in the window and put them away. A few minutes later, I hear tapping at the window, when I would turn around to see the bird, it would fly away. This happened for an hour or so and then Princess Five came in and I asked why the books were in the window. She said she was using them like scarecrows to try and keep the bird from freaking out. 

She then pointed out the bird drool / feather marks on the window. I then noticed poop all over the brick and as you can see in the video, the other window brick has NO poop on it as we have never had a bird do this before! 

I was working on the computer for hours and even after putting up six books in the windows, that bird attacked the windows for hours and hours and just before the sun went down, it started chirping at me and telling me off! It was so upset! 

I have never seen this before and have no idea what was going on with the bird but it is NOT a happy bird! It is too early for eggs and nest so I have no idea why it was freaking out at the window. I wonder if hitting the window originally caused some brain damage or something. 

I am a little worried it may come back tomorrow. I don't know what I will do with this crazy bird if it continues its rant. I wonder what it would do if I opened the windows. When we were in the basement, it was looking in those windows. I thought perhaps it had a baby that fell into the window well before I realized that it is a bit early for that. Anyone have any ideas as to why a bird would do this? 
 
I am so glad I didn't get to washing the windows last week! I worked on the front yard garden beds but it got cold and rained and then snowed so I'm happy that I didn't have to wash them twice! I do feel sorry for the bird as it's poor beak has got to be hurting pecking at the hard glass all day!