cats are almost liquid (in a way)

We all know by now that cats can fit into just about any shape they want. Their flexible bodies and agile movements allow them to squeeze into boxes, bowls, and just about any tight space they want. Now a researcher has gone even further and explored the question of whether cats know they are behaving like liquids.

In this context, the term ‘liquid’ is of course used metaphorically. Cats can shape themselves to fit into different spaces, just as a liquid takes the shape of a container. Scientifically speaking, liquids are substances that flow and conform to the shape of whatever contains them, without a fixed shape but with a consistent volume. When applied to cats, the idea is that their bodies are incredibly flexible, allowing them to stretch, compress and twist to fit into tight or oddly shaped spaces.

But there is another aspect to it: cats’ self-awareness. To know that they can fit in these non-intuitive places, cats must be remarkably self-aware to gauge where and how they can fit.

Self-awareness in animals is generally associated with cognitive complexity. This is often tested via the well-known mirror test, in which an animal is observed to see whether it can recognize itself. Passing the mirror test indicates a form of self-representation: the ability to distinguish one’s own body from the environment. However, self-representation can manifest itself in different ways, not only through visual recognition, but also through spatial awareness – knowing how one’s body fits into the physical world.

Cat geometry

Biologist Péter Pongrácz from Eötvös Loránd University in Budapest wanted to test whether cats are aware of their size when navigating through small openings. Particularly aimed at companies that are pushing the limits of their flexibility. In other words, Pongrácz wanted to test whether cats know they are ‘liquid’.

The experiment involved 30 domestic cats, each confronted with increasingly smaller openings in a panel (a total of 38 cats were included in the study, but only 30 completed the experiment). These openings had a fixed height or width, and the goal was to observe how cats would react when confronted with openings that were, in some cases, smaller than the cat’s chest width or height.

As the study progressed, the researchers noticed something intriguing: Although cats quickly approached tall but narrow openings without hesitation, they slowed down significantly when approaching shorter openings. They hesitated, especially if the height of the opening was less than the cat’s height at the withers (the highest part of a cat’s back). In these cases, some cats even looked for alternative ways to get past the obstacle, such as jumping over it.

“Remarkably, cats showed hesitation both before attempting to enter the shortest openings and while passing through them. This “aperture test” requires a decisive response from the participant before contacting the opening as evidence of his dependence on the mental representation of his own size and/or shape,” the researchers write in the study.

High versus wide

These observations suggest that cats use a mix of strategies when deciding whether to move through a space. When the opening is large enough, they rely on their body’s flexibility and experience, squeezing through with little effort. But if the height is uncomfortable, they pause, seemingly aware that their bodies may not fit.

Interestingly, the study found that taller cats were more likely to hesitate or seek alternative solutions when the opening was uncomfortably short. This suggests the possibility that body size plays an important role in how cats perceive obstacles in their environment, and that they may be more sensitive to vertical constraints than horizontal ones.

Cats’ whiskers, or vibrissae, may also play a role in this learning process. These highly sensitive hairs are located on their faces and can detect nearby objects, helping cats judge whether they can pass through a narrow space. This tactile feedback can supplement their visual assessment, helping them make more accurate decisions about the space.

An elegant experiment

The first question researchers wanted to answer was whether cats make a conscious decision based on their body size before attempting to pass through a small opening. The results show that although cats do not always make a clear decision before approaching narrow spaces, they show clear signs of body awareness, especially when confronted with shorter openings. This suggests that cats don’t rely purely on trial and error to overcome obstacles. Instead, in certain contexts they rely on a mental model of their own size.

This makes sense considering the lifestyle of cats. Unlike dogs, which often chase their prey over long distances, cats must be stealthy and agile. They often navigate complex environments, climbing trees, squeezing through tight spaces and jumping from high places. In these scenarios, a miscalculation can be dangerous.

This conclusion was only possible thanks to the clever design of the experiment. By incrementally reducing the size of the openings and observing the cats’ responses, the researchers were able to assess not only physical agility, but also cognitive processes such as self-representation. The design is simple, yet provides insight into how cats use both trial-and-error and mental models of their own size to deal with challenges.

Implications for cat cognition

This study also suggests that cats are capable of more complex thought processes than often believed. While they may not exhibit the same level of self-awareness as some other animals, such as great apes or dolphins, their ability to assess space and adjust their movements accordingly indicates a level of body awareness that is quite remarkable.

For pet owners, this study provides practical insight. It suggests that cats are excellent at judging whether they can fit through a space, which could explain why they seem to effortlessly slip through gaps that seem impossibly small.

However, it also highlights the importance of providing cats with an environment in which they can exercise this natural ability. Obstacles such as tunnels, climbing structures and narrow passageways can help keep a cat’s mind and body engaged, allowing him to hone his spatial awareness skills.

The research was published in the journal iScience.