I have a pair of blue birds in my blue bird house about 4 feet from my large picture window that over looks a pond and the back yard.  The picture window acts like a huge mirror for all the wild life and water.  The nesting blue birds see all (including themselves) and are pecking at the window.  It is very interesting to be able to see them so close because they can not see me standing there.  But I am concerned that they are going to hurt themselves.  I have been told to place something metallic that swirls, but I do not want to scare them away from their babies in the box!   HELP!!!!!!!!!!!!!!!!!!!!!!!!!