Cardinals that fly into the windows surrounding your home are annoying for you and dangerous for the birds. These birds fly into the glass for a number of reasons. Sometimes the glass is invisible to cardinals because of its transparency. Other times, the birds mistake a reflection of open space for true open space, and try to fly into it. Cardinals are also very territorial and see their own reflection as a threat, mistaking it for another bird.

Step 1

Install netting or screens on the outside of your windows. This is the most effective method of keeping cardinals from running into the glass.

Step 2

Move bird feeders closer to the windows, disrupting the cardinal's flight path. Putting a bird feeder one to three feet from a window makes it more likely the cardinals will see the window and avoid hitting it.

Step 3

Dull the reflection from the window by applying fake snow or oil on the surface. As an alternative, apply plastic food wrap to your window surfaces or refrain from washing your windows and let dirt build up.

Step 4

Stick decals on the glass to alert cardinals to the presence of the windows. If the window is very large, use more decals. For smaller windows, place the decals in the center of the pane. You can also position loose tree branches in front of your windows by suspending them from the window frame to deter the cardinals.

Step 5

Hang reflective balloons outside of the effected windows. The reflections that bounce off of the balloons will scare the cardinals away, as will the physical movement of the balloons. You can also string CD's, colored balloons or foil pie pans around the windows to achieve the same effect.