Put something on the outside of the windows to break up the reflection: decals, streamers, tape, anything as long as it's on the outside of the window.

I had a few cardinals that were in love with their reflections of themselves in the side mirrors of my vehicles and they made a mess all down the sides of the vehicles. I had seen that happen to a neighbor too....only the cardinals did it. I tied bags over the mirrors and they soon moved on and have had no problems since.

My suggestion to you is to give them their own mirror outside somewhere near the window...and then try moving it a little at a time, until you have it where you might like it best. My guess is that they will find and use the mirror and then leave your windows alone.

Good luck

Sue

I had the same problem with a Cardinal and my car. She would fly around banging into the windows and mirrors, and make a mess everywhere. I thought it was just protecting its territory against a strange bird. Not real bright even for a bird.