How to Stop Birds From Attacking Windows

Northern Cardinals sometimes attack their reflections in windows during the spring.

You’re enjoying some blissful sleep, when suddenly, you’re woken by an incessant tapping at your window. Cozy and content in your warm refuge, you try to ignore it, hoping it will soon stop.

It doesn’t. Begrudgingly, you get out of bed and open your blinds to find a bird at your window, aggressively fighting an unseen enemy with its beak, feet, and wings.

Many people have had this common spring-time experience of a bird repeatedly attacking their windows. Why do birds do this, and how can you stop it?

Why birds attack windows

Territorial aggression is at the root of this behaviour. The bird has spotted its own reflection in the window and sees its mirror image as an intruder in its territory. They will then do everything they can to scare this trespasser away.

NOTE: Territorial aggression is different from the serious issue of bird-window collisions. Countless birds become killed or injured from flying full speed into reflective or transparent glass. Learn how to stop birds from hitting windows at your home or cottage.

This type of behaviour is common in the breeding season when birds are starting a family and actively defending their breeding territories. Species that nest in the trees and shrubs of suburban yards (like American Robins, Northern Cardinals, and Chipping Sparrows to name a few) are often the most frequent culprits.

Depending on the breeding biology of a particular species, birds might start defending their territory (and attacking the ‘intruders’ they spot in home windows) as early as February or March and could continue until August. Some species may only attack windows for a week or two, but some that raise multiple broods may continue longer.

Will the bird hurt itself?

Although these attacks can look vicious, the behaviour doesn’t usually result in injury or death. However, it has the potential to lead to minor injuries to a birds’ beak, minor abrasions, and exhaustion.

How to stop a bird from attacking your window

Sometimes, it’s ok to simply be patient and wait. This behaviour will subside as the breeding season progresses and the young leave the nest.

However, if the bird is impacting your ability to sleep or work, the only way to stop the attacks is to eliminate the bird’s reflection in your window. Although closing interior blinds or drapes is often one of the first things people try, this often actually makes the reflection stronger. Here are some more effective methods to obscure the bird’s reflection and stop them from fighting your windows.

Cover the window

One option is to hang or place something on the outside of the window. If letting in natural light is important to you, consider affixing a medium weight plastic painter’s drop cloth or a clear plastic shower curtain to the outside window frame with double sided tape or a few small nails and a hammer. Non-reflective cellophane is another option.

If the view isn’t important, try taping newspaper or a piece of light fabric to the outside of the window. If you have exterior shades or blinds, you can close those instead.

Soap the window

Mute reflections by applying soap to the outside surface of the window for a few weeks during the nesting season. Choose a bar of soap that will leave an opaque, white film when wet (such as Ivory) and coat the entire outside surface of the window. Reapply as necessary (e.g., after heavy rains).

Use a lamp

Shine a lamp out through the window during the day to create a bright glare and mute reflections.

Try perforated window film

For a more permanent option that also prevents bird-window collisions, cover the outside of your window with perforated window film such as CollidEscape.

Install an exterior window screen

Exterior window screens can help to mute reflections and do not allow birds to access the window.

A bird is attacking my car! What should I do?

A Gray Catbird attacks its reflection in the shiny chrome bumper of a parked vehicle. Photo: Karen Bleier.

Cars, with all their shiny surfaces, can also become the target of these attacks. The same principle of trying to eliminate reflections applies. Here are some options:

If you have adjustable side mirrors, pivot them inwards when you park
If you don’t have adjustable side mirrors, secure a grocery bag over the side mirror with a rubber band while you are parked
Use a tarp to cover other reflective areas
Try parking your car outside of the bird’s territory