The window with the issue is in the front of the house, facing the road. We have curtain panels which close entirely across the bay. But they aren't stopping a wacky female Cardinal from banging her bill against the panes. The curtains were closed this morning and she's still hitting glass. I read the above article. They say let the window stay dirty and it won't reflect as much. Well she doesn't stop banging it long enough for us to clean it. And that's annoying. I love clean windows. We've lived here 34 years and this the first time I remember this sort of thing being an issue.