From Fatal Light Awareness Program (FLAP) Canada:

Far too often we see disturbing products like this: they promise you privacy and climate control, but fail to inform of the numerous birds that will die once installed.

Birds collide with glass for two primary reasons: either they can see through the glass to something desirable, or they are attracted to reflected habitat.

There are many cost efficient solutions to create privacy at home that don’t put birds at risk: flap.org/stop-birds-from-hitting-windows. Mirrored films like this product from Window Film World, should be avoided.