Why Some Bird Lovers Put Aluminum Foil On Their Windows (& Should You Try It?)

You hear a thud on your window and get that sinking feeling. There are no kids nearby to accidentally throw a ball at the glass, so that means yet another native sparrow or pretty yellowthroat has flown into it, injuring themselves or, sadly, worse. Well over 200,000 birds a year are killed in window strikes in New York City alone. Of course, you don't want to add to these statistics. How can you prevent birds from flying into your windows? It turns out the solution may be sitting in your pantry. Adorning your window with sheets or strips of aluminum foil is widely recommended by avian professionals as a window strike deterrent, with few naysayers. Should you try it? Resounding expert consensus suggests yes.

Birds strike windows because they don't know they're there. Glass is reflective, and the birds see the sky and garden reflected in the glass and think they can fly right through it. In other cases, some territorial male birds mistake their reflection for a rival and slam themselves into the glass — often repeatedly — in an attempt to fight them. They also may be attempting to chow down on trapped insects. Several Audubon chapters say shiny things moving on a window, like strips of aluminum foil, make for an excellent discouragement. The sentiment is echoed by the British Trust for Ornithology, too. The foil also breaks up that trouble-causing reflection, according to wild animal rehabbers PAWS, an idea reinforced by the Nebraska Extension in Buffalo County.

Only a smattering of specialists (including, suspiciously, sellers of bird deterrent products) dislike aluminum foil, dissuading people from using it. In her 1994 book For the Birds: An Uncommon Guide, bird authority Laura Erickson suggests bird feeders mounted to the window work just as well as foil and look better. It's a good reason for bird lovers to clean their windows less often, too. Additionally, some city housing programs and homeowners associations ban people from attaching the shiny stuff to windows. In rare cases, birds might try to use the aluminum foil as nesting material and get tangled in it.

If you've decided to give this idea a go, most experts suggest taping strips of aluminum foil to your window. The idea is to let them move about, adding an extra layer of bird deterrent. If you're looking for something more precise, cut the foil into 1 foot squares and tape a few to the window. Tin foil pans work well, too, with the bonus of making a clattering sound if the wind picks up. Another strategy is to affix aluminum foil sheets to the inside of the panes and the outside sill of your window. If you don't want to keep the aluminum foil up permanently, try affixing it to your windows at least from May to September — research indicates bird strikes peak at this time.