Millions of wild birds are killed each year flying into windows. Now you can help reduce this loss of life. WindowAlert is a static-cling decal that is easy to apply and peel off glass. Use Window Alert decals on home and office windows. Each decal contains a component which brilliantly reflects ultraviolet sunlight. This ultraviolet light is invisible to humans, but glows like a stoplight for birds. Birds have vision that is up to 12 times better than that of humans. WindowAlert decals help birds "see" windows and thus avoid striking the glass.