why do birds fly against my window, are they blind?

If you stand outside and look at your window many times you see a reflection of the trees and sky...

The birds often see this same reflection and think it is ok to fly in that direction , only to find out too late that it is not...

Millions of birds migrate.In the fall, birds tend to migrate at night behind cold fronts, and bad weather forces them to land.

Birds end up in the canyons of city buildings, where lights might confuse and disorient them, resulting in collisions because Lights increase the density of birds near the hazard. Birds are attracted to light.

Artificial light is not part of a bird's natural environment as a result, many birds end up in cities and crash into windows, which they can't see and also to the fact that reflection of sky confuses them most of the time.

Birds don't understand window glass and can easily crash themselves when they fly into glass.

I had a red bird that would always fly against my window and I was told that it was seeing its reflection and thought it was another bird and that it trying to get to it.

Also if the winow is too clean the bird doesn't see it as a barrier and tries to fly through it. Hang some blinds and they'll stop.

depending on the season, birds eat berries off of evergreen bushes, and these berries often make them intoxicated, which causes them to loose their perception of the things around them, and they fly into things they normally wouldn't fly into.

they see a reflection of the area around them in the window.

No. The reflection of the sky is what throws them off.

Try hanging something on the window...like a sun catcher.

No, they just don't give a damn.