“Cat flap” cat “cat door” entered the Oxford English Dictionary in 1957 and 1959, respectively, but the idea comes much earlier in history.
When farming began thousands of years ago, people noticed that wild cats did not eat grain but were good at chasing rodents and cleaning up insects.
So they installed small doors (or simple holes) so that the cats could enter the barns. This practice continues today in several places.
Modern cat doors designed for pets are much more luxurious. There is usually a weighted leaf on the inside. Often they have springs to close the door against the wind or have magnets on the edges for the same purpose.
Some cat doors have a mechanism that allows them to open in only one direction, for example, allowing the cat to enter but not exit (although intelligent cats have figured out how to handle this).
Indeed, luxury models have a “key” for opening only for animals, be it collar magnets or implanted microchips.
The video below is an old but good picture from 1999. This cat is quite well-fed, so it requires some effort.
Then, quite unexpectedly, a young deer enters through the door of the same cat. The deer is much bigger than a tuxedo cat, but the deer is surprisingly flexible and makes its way quite easily.
You almost realize that this deer has done it before.
We have no idea if the cat or deer were friends or just strangers who took turns using the cat door. Can you imagine the surprise that awaited when a beloved deer passed by that little deer?
