Alfred Hithcock wrote "the birds", but we much rather fact, not fiction.
Firstly, ask Why?
In today's selfish world it's so easy to think that you have kamikaze birds and their Intention is to smash your windows and cause you expensive repairs.
However, if stop watching too much TV, and/or realise that Alfred Hithcock wrote fiction, you'll instead think, as you should, of nature and reality.
Look online and you'll see loads of rubbish telling you about birds sending you a message from the universe about adjusting your life, blah, blah, blah.
So the old wives tales appear to have developed into fictional stories nowadays - so switch your head on.
In the real world, birds don't pay money to fly, squirrels don't pay money to climb trees, cats don't pay money to eat, nor do they pay money to live, so why do we? Who invented money? and why?
In todays world of "look at me, look at me" window cleaners do help to create the delusions of wealth and care, to the outside world. Think.
Birds don't see that, rather they see your clean, polished windows as mirrors, and birds don't have the huge amount of "brain power" that humans are supposed to have, so birds will see their own reflection in your windows, and think that another bird is flying past, so they will effectively attack themselves. This is more prevalent when mating and breeding times occur; as the boy birds can get a bit territorial!
So ridding the birds of their own reflection is all you need to do to stop them from attacking 'themselves' really. The next question is how?
The picture posted at the top of this page is a link, just click the pic for more choices of patterns. 👍
The real challenge that birds present
A bird, flying at speed into your window, is likely to cause a bit of a noise, but think about how much more likely injury to the bird will be, so dont be selfish (which frankly is far too evident these days), and instead just genuinely care for nature.

Protect your buildings, and birds
We understand the delicate balance required when dealing with birds.
Our approach focuses on simple, low cost solutions that will help to protect your building, all you need to do is stop assuming that old wives talked sense.