I have one way glass on my windows, the same type that’s used in police interrogation rooms. So I can see out but people looking in only see their reflection.
So one morning I hear this insistent tap on the windows and I nearly jumped out of my skin. After a while I realised it came from outside, this bird was perched on my plants and pecking at the glass. It took me a second to realise it was seeing another bird and was probably trying to communicate with it.
Now it happens almost every morning, often there’s 2 or 3 of them, all pecking and flapping their wings at their non-existent cousin. It’s a funny sight.