Prevent Birds from flying into your window

 I saw this on a YouTube video, made by Alex Sally,  Incredibly simple tip to prevent birds flying into window. It only took me eight years to find this video.

I have had birds of all sizes crash into one particular upper window of our home. 

After watching the video, I went out and found a white marking paint/pen for less than $3.00,

I drew about a four inch tic tac toe board on the window, and the bird hits have stopped! Such a cheap and easy fix!