Last Updated on September 9, 2026 by admin
Put a square of masking tape on your floor and your cat will sit in it. Not beside it. In it, dead center, like the tape was a chair you finally got around to buying.
Most owners file this under general cat weirdness. It gets a photo, a laugh, and a post tagged #CatSquare. The usual explanation is novelty — something new appeared on the floor, so the cat investigated it and then, being a cat, sat on it.
That explanation is wrong, and there is a study that proves it using a square that did not exist.
The square doesn’t have to be there
In 2021, a team led by Gabriella Smith, an animal cognition researcher at Hunter College in New York, published a paper in Applied Animal Behaviour Science under a title no journal editor should have permitted: If I fits I sits.
The question was whether a cat would sit inside a square that was purely an illusion.
The tool was the Kanizsa square — four circles with a 90-degree wedge cut out of each, arranged so the wedges point at one another. Your brain connects the corners and draws four sides that are not printed on the paper. It is one of the oldest tricks in vision science, and you fall for it every single time you look at one.
Sunglasses, six days, and a lot of dropouts
Owners printed the shapes at home and ran the trials themselves. Shut the cat out of the room, lay the options on the floor, then put on sunglasses so the cat could not read where you were looking, let it back in, and film for five minutes.
The sunglasses matter more than they sound. Cats track human gaze well enough that a researcher glancing at the correct answer can hand them the correct answer.
More than 500 people signed up. 121 finished the first trial. Thirty made it through all six days — a number that says as much about cats as it does about people.
What the nine cats did
Of those 30 cats, nine sat or stood inside a shape for at least three seconds.
They picked the real taped square eight times. They picked the illusory Kanizsa square — four corners and nothing between them — seven times. The scrambled control, using the same four circles rotated so no square appears, was chosen once.
Nine cats sat down inside a square made of nothing but four corners, and their brains supplied the missing sides.
“Cats’ susceptibility to the illusion informs us that they perceive contours (illusory or otherwise) as humans do,” Smith told Zazie Todd at Companion Animal Psychology. Her own cat, Pancetta, was photographed parked squarely inside one of the illusions.
So it was never about the tape
This is the part that changes how you read your own cat.
Your cat is not drawn to the tape, the paper, or the novelty. It is drawn to edges — and its visual system is willing to invent the walls when the corners merely imply them. As Smithsonian magazine reported on the study, the cats appeared to be responding to contours rather than to something simply being new on the floor.
There is a reason enclosure ranks that highly. A house cat is an ambush hunter that also happens to weigh about nine pounds, which makes it prey for coyotes, loose dogs, and larger cats. A boundary on four sides is where both of those jobs get easier.
The effect is strong enough to show up in welfare data. In a Utrecht University trial of newly arrived shelter cats, cats given a simple hiding box recovered from arrival stress at least four days sooner than cats housed without one.
What to do with this
Take the four-sided thing seriously. A cardboard box on the floor, a shelf with raised edges, a covered bed in a quiet corner — your cat is not being sentimental about cardboard, it is reading a boundary and relaxing inside it. Cats under stress, in a new home, or recovering from a vet visit need that option available and unblocked.
Then go have some fun with it. Four strips of tape, ten seconds, floor.
Your cat will find the square. Even if you leave the sides out.
Does your cat do this? We need to know. 🐱