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The Cat Flap: Invented by Isaac Newton!

3 minutes
The cat door seems to be a very obvious invention that anyone could have thought of, but here we tell you how it came about.
The Cat Flap: Invented by Isaac Newton!
Last update: 21 December, 2022

The cat flap is one of the most useful inventions for cats in our homes, but did you know that the first one was invented primarily for the benefit of its creator, who was none other than Isaac Newton himself? Or, at least, that’s what Cyril Aydon tells us in “Scientific Curiosity.”

Aydon credits Newton with pioneering this invention because the scientist came up with a prototype of the device that today has many variants. As he tells it, Newton needed to concentrate on his research very carefully, but his cat meowed all the time to be let in and out of the house.

Knowing how demanding cats are, we can’t imagine one of the fathers of modern science getting distracted at every turn to please his pet. So he came up with the idea that she herself could go in and out as she pleased without any help from him. Thanks to this, the first cat flap was a hole in the bottom of a door of the Isaac Newton house.

What about modern cat flaps?

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The scientist’s story doesn’t end there, in fact it gets very funny. Newton’s cat got used to wandering around and hanging out with other cats in the street, and got herself pregnant. When the kittens were born, Isaac Newton, one of the most brilliant minds in history, couldn’t think of anything else to do but make a smaller-sized hole for the kittens to go in and out of.

It’s ironic that it didn’t occur to the scientist that the kittens could use the same hole as the mother to go in and out of the house!

However, this “cat hole” was far from perfect. The holes allowed more light to enter the room than he wanted, and it was harming his experiments, so he decided to cover them with felt, to ensure the cat and kittens could come in and out easily. So, Newton’s cat flap was now very close to the real thing!

Today, there are several designs, the most common being a hinged panel, such as the doors of the litter boxes for cats. However, some models are so advanced that they include a spring for protection against wind and rain.

But these are nothing compared to those controlled by technology, which are able to identify by radiofrequency the location and reading of the microchip that we put in our pets, making the use of the collar unnecessary.

Uses of the cat flap

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The cat flap can be placed in areas where we don’t want the dog to enter (if it’s a large dog) so that it doesn’t eat the cats’ food. It’s a great invention that also reduces or completely eliminates the meowing and scratching that they make on the doors for us to let them in and out.

But, without a doubt, the best use of the cat flap is as their door to shelter when the weather outside becomes inclement. The best thing for them is to know that they can always come back inside whenever they want.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • “Primera puerta para mascotas con certificación de casa pasiva del mundo presentada en Ecobuild 2014” . www.gizmag.com . Consultado el 7 de julio de 2016 .
  • “Puertas automatizadas para mascotas: puerta para mascotas” . Consultado el 7 de julio de 2016 .
  • “PetWALK puerta automática para mascotas evita marcas de patas mojadas alrededor de la casa” . Ubergizmo . 2014-03-13 . Consultado el 7 de julio de 2016 .

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.