Millions of birds die every year, because they can't tell reflections from reality. Almost half hit home windows.

Never had a bird hit your window? More likely, you haven't been there when it happened. But the odds are that sooner of later, your windows will kill a bird.

Even small windows can be dangerous, as many birds fly into small spaces.

ABC has identified solutions that work. Most birds will avoid patterns on glass with vertical stripes four inches apart or less, or horizontal stripes spaced two inches or less apart. Stripes should be at least ⅛" wide and readily visible. Irregular patterns that follow these guidelines will work too.

Windows with screens should already be safe for birds.

Here are some quick and affordable ways to protect birds from your windows. These should be applied to the outside of the glass.

• Apply Tempera paint freehand with brush or sponge, or use a stencil as a template. Tempera is long-lasting, even in rain, and non-toxic, but comes off right with a damp rag or sponge.
• Use tape to create patterns. Any opaque tape can work, but translucent ABC BirdTape transmits light and is made to last outdoors.
• Most window films designed for external use are not patterned and will not deter birds. However, there are good options. White CollidEscape is see-through from the inside, opaque from the outside, Solyx Bird Safety Film has narrow horizontal or vertical stripes. With Feather Friendly's 'do it yourself' tape, the baking is pulled off, leaving just the pattern.
• If you don't want to alter the glass itself, Acopian Bird Savers (also known as Zen Wind Curtains) are unobtrusive, as well as highly effective.
• You can protect birds with lightweight netting over the window or removable screens. Several companies sell screens or other barriers that can be attached with suction cups or eye hooks. Or use a motorized solar shade to make glass safe when you're not there. These options must be several inches in from of the window, so birds don't hit the glass after hitting the net.
• What about prefabricated decals? Birds see decals shaped like raptos as obstacles but not as predators. To be effective, any type of decal must be shaped as described earlier, more closely than recommended by most manufacturers.