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How to Stop Birds Attacking Windows (Why Do Robins Knock on Glass?)

Friends say I have "green-fingers," and the garden certainly responds to my efforts. I enjoy watching wildlife and being outdoors.

A bird attacks and hits its own reflection in a car window.

A bird attacks and hits its own reflection in a car window.

Unusual, Aggressive Bird-Pecking Behavior

Have you ever been sitting quietly at home or in your car when a bird starts to attack the window? A robin recently used my living room window as a target and flew repeatedly at the glass. These demented attacks on their reflections on a window pane or car wing-mirror can last from 10 to 20 minutes. The same bird may repeat this action several times a day.

If you’ve never seen this type of bird behavior, take a look at the video below. It shows a cardinal repeatedly throwing itself against window in the same manner as the one in my garden. This strange behavior can last for several weeks.

Ways to Stop a Bird From Tapping or Pecking at Your Window

The best way to prevent a bird from attacking your window is to break up the reflection of its image so the bird doesn't attack its reflection thinking it's a competitor.

  1. Use highlighters to draw a grid on your window: This is the best method. It works immediately and is recommended by the Texas Parks and Wildlife Service. Birds can see the highlighting, but it is barely visible to humans.
  2. Cover up the window: You could break up reflections by leaving the window dirty or by using decals. This doesn't really work and stops light from entering the room.
  3. Use stick-on deflectors or shiny objects (old CDs) to break up reflection and distract: Shiny hanging objects aren't very effective, but stick-on deflectors can work and are easy to apply.
  4. Close exterior shades and blinds: This is not really an effective solution as you are sacrificing daylight and views for the sake of preventing birds pecking at the windows.
  5. Shade the window with an awning: This may work as it breaks up reflections, but can be an expensive option.
  6. Install wind-chimes or water-fountain as a distraction: These are fun to have but are not an effective bird deterrent.

Stop Pecking by Removing Reflections

The advice given by the RSPB (Royal Society for the Protection of Birds, a British wildlife charity) to prevent birds attacking panes of glass is to cover the outside of targeted windows with non-reflective cellophane. The problem with this is that wind and rain will quickly make the cellophane come adrift and ineffective.

Their alternative suggestion is to cover the inside of affected windows with newspaper or lots of decals. Or you could leave curtains and blinds drawn to make the glass non-reflective. However, there’s a huge disadvantage to these solutions. The birds may stop pecking your window, but you will no longer be able to enjoy looking out through it.

You could use a medium-weight plastic painter's drop cloth instead. The cloudy plastic will allow you to see out and let a reasonable amount of light enter, but will eliminate the bird’s reflections. The idea is to attach the plastic sheet to the top of the outside of your window and leave it to hang loosely. Any movement in the sheet caused by breezes will help to scare away the bird.

I have found that a Bird's Eye View window deflector works well. It breaks up the clear view of the glass for birds and stops them striking at their reflection. At the same time it's small enough not to obstruct your view of the outside. It's also easy to remove from the window if you should want to.

How to Stop Birds From Attacking Windows

Draw Gridlines on Your Window Using Highlighters

The best solution I’ve found to this problem is one recommended by Texas Parks and Wildlife Service. It involves drawing grid lines on your windows using fluorescent marker pens (highlighters). It’s cheap and easy to do. It can be done from inside your property so there’s no need to worry about climbing ladders. Best of all, it works!

How It Works:

The pigment in the highlighters can be seen by birds but is difficult for humans to see, so it doesn’t interfere with your view out of the window too much. Drawing a grid of lines with a fluorescent marker breaks up a bird’s reflection, so the repetitive pecking behavior stops. The effect is virtually instant.

I use Sharpie Tank Highlighter Marker Pens. Their tanks contain enough ink to draw a grid over the whole window, and their quick-drying ink means that smudging is minimized.

The video below was made by the Texas Parks and Wildlife Service and demonstrates the difference in bird behavior between a marked window and an unmarked one. It is remarkable the difference a few highlighter lines can make.

How to Keep Birds From Hitting Your Windows

Summary of Texas Parks and Wildlife Service Method

  1. Clean the inside of your windows using a propriety glass cleaner.
  2. Next, use a highlighter to draw a grid of lines on the inside of the affected window. (This is the one that the bird is using for its target practice.)
  3. The horizontal lines should be less than 2” (5 cm) apart. The vertical lines need to be no more than 4” (10cm) apart.
  4. You will need to reapply the grid every week or so as daylight will gradually fade the florescent ink.
  5. That’s it. The job is done. Problem Solved!
  6. Now you can sit back and enjoy birdwatching without the head-banging tactics.

Do Shiny Balloons Scare Away Birds?

Some people think that hanging balloons in front of glass will frighten away wildlife, but they're not an effective deterrent. A good guide to bird behavior is What it's like to be a bird: It will help you understand the way birds see the world, from flying to nesting, eating, and singing.

Hanging shiny items like CD discs can scare birds away, but you need to keep them constantly moving to have any real effect.

The American Robin (Turdus migratorius) may peck at windows in the US.

The American Robin (Turdus migratorius) may peck at windows in the US.

Why Do Birds Fly Into Windows?

Birds fly into windows for three reasons:

  1. They fly into a reflection of a tree or plant thinking its real. When birds see reflection of vegetation or they see through the glass to indoor plants, they fly straight for it at full speed.
  2. Male birds attack their own reflections to defend their territory. These attacks take place most often in spring (the breeding season) and in the fall (when birds are newly arrived on migration from another country). Scientists believe that birds attack their reflection in the glass thinking it's a rival bird.
  3. Night-migrating birds become disoriented by lighted windows. Because these birds navigate by starlight, artificial building lights can confuse them and divert their migration patters. Birds either collide with the windows or they hover around lighted windows until they get exhausted. A single lit city building can kill thousands of migrating birds in just one night.
The European Robin (Erithacus rubecula) often knocks on windows in the UK.

The European Robin (Erithacus rubecula) often knocks on windows in the UK.

Territorial Birds That Attack Windows

American goldfinch

American robin

California towhee

Chipping sparrow

Eastern bluebird

Eastern towhee

European robin

Gray jay

Gray wagtail

Laughing kookaburra


Northern cardinal

Northern mockingbird

Ruffed grouse

Song sparrow

Wild turkey

Yellow-rumped warbler


This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.


AubreyW on May 31, 2018:

A little over a month ago I started getting two ravens pounding on my basement windows. It happens anytime between 4:30 am and randomly throughout the day. It sounds like they are beating a drum with their huge beaks. I've tried closing the blinds, putting a full size hawk picture in the window, shooting at them with a pellet gun and newspaper. Nothing has worked so far. I am going to try the highlighter and see if that works. I hear them outside as I right this, hope this works.

RedElf from Canada on April 19, 2018:

Every once in a while a nuthatch will smack into the front window - usually during migration in the late spring. Unfortunately, they usually don't survive. We have been told it's because the poor critter didn't see the glass. I have never seen anything like the behavior of your robins and bluebirds though, I bet the grid would probably fix the "fly-through" problem as well. Nifty idea - and simple - like all the best ideas. Thanks for the great info.

Ann Carr from SW England on November 12, 2015:

Fascinating! I've never had my windows attacked like that but we have had birds fly straight into them, not realising there was an obstacle, mostly blue tits and finches.

The highlighter solution is a clever one.

Lovely photos too!