It is estimated that as many as 975 million birds are killed each year in North America in collisions with glass windows and buildings. Windows which reflect the sky and habitat around them create a deadly optical illusion for birds. We think Feather Guard is very effective in preventing birds from striking windows. It combines bright colors and motion. Feather Guard consists of two suction cups with brightly colored feathers attached to a line in between. The feathers will then move in the slightest breeze which helps break up the reflection on the windows. The combination of bright colors, loose feathers (which birds also avoid because it makes them think a predator has been present) and the motion of the feathers helps keep your birds safe. Feathers are naturally dyed. Installs in seconds and does not obstruct view or block light. We believe these Feather Guards are much more effective than window decals.