Stop Birds from Flying into Windows

For several years, a male cardinal has been repeatedly flying into my friend's bedroom window from dawn until about noon. It happens every season except summer, when she has a screen on the window. What can she do to stop this bird?

—Patricia Bonneau, Lewiston, Maine

George: Male and female cardinals often fight their own reflections in windows because they're trying to chase the "other bird" from their nesting territory. American robins, mockingbirds and other birds will do the same thing. To alleviate this problem, eliminate the reflection by leaving the screen in year-round, soaping the window or hanging streamers. If that doesn't work, try covering the window from the outside.