By now, we all know that cats can fit into pretty much every shape they want to. Their flexible bodies and agile movements allow them to squeeze into boxes, bowls, and pretty much every tight space they fancy. Now, one researcher has taken this further, exploring the question of whether cats know they behave like liquids.

In this context, of course, the term “liquid” is used metaphorically. Cats can mold themselves to fit into various spaces, much like a liquid takes the shape of its container. Scientifically, liquids are substances that flow and conform to the shape of whatever holds them, with no fixed form but 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’s another aspect to it: cats’ self-awareness. In order to know they can fit into these non-intuitive places, cats must be remarkably self-aware to estimate where and how they can fit.

Self-awareness in animals is typically associated with cognitive complexity. It’s often tested through the well-known mirror test, where an animal is observed to see if it can recognize itself. Passing the mirror test suggests a form of self-representation — the ability to recognize one’s own body as distinct from the environment. However, self-representation can manifest in different ways, not just 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 small openings. Particularly focusing on those that challenge 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 progressively smaller openings in a panel (overall, 38 cats were included in the study but only 30 completed the experiment). These openings were either of fixed height or width, and the goal was to observe how cats would react when faced with apertures that were, in some cases, smaller than the cat’s chest width or height.

As the study progressed, the researchers noticed something intriguing: while cats were quick to approach tall but narrow openings without hesitation, they slowed down considerably when approaching shorter openings. They were hesitant, particularly when 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 sought alternative ways to get past the obstacle, like jumping over it.

“Remarkably, cats showed hesitation both before they attempted to penetrate the shortest openings, and while they moved through it. This “aperture test” requires a decisive response from the participant before it would make contact with the opening as proof of its reliance on its mental representation of their own size and/or shape,” the researchers write in the study.

Tall versus wide

These observations suggest that cats use a mix of strategies when deciding whether to pass through a space. When the opening is tall enough, they rely on their body’s flexibility and experience, squeezing through with little concern. But when 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 points to the possibility that body height plays a significant 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 face and can detect nearby objects, helping cats judge whether they can pass through a narrow space. This tactile feedback may supplement their visual assessment, allowing them to make more accurate decisions about space.

An elegant experiment

The first question that 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, while cats don’t always make a clear decision before approaching narrow spaces, they show clear signs of body awareness, especially when faced with shorter openings. This suggests that cats are not purely relying on trial-and-error to navigate obstacles. Instead, they are drawing on a mental model of their own size in certain contexts.

This makes sense considering cats’ lifestyle. Unlike dogs, which often chase down prey over long distances, cats need to be stealthy and agile. They frequently navigate complex environments, climbing trees, squeezing through tight spaces, and leaping from high places. In these scenarios, a miscalculation could 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’ reactions, the researchers could assess not only physical agility but also cognitive processes like self-representation. The design is straightforward, yet it provides insight into how cats use both trial-and-error and mental models of their own size to navigate challenges.

Implications for cat cognition

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

For pet owners, this research offers some practical insight. It suggests that cats are more than capable of judging whether they can fit through a space, which may explain why they seem to effortlessly slip through gaps that seem impossibly small.

However, it also highlights the importance of providing cats with environments that allow them to exercise this natural ability. Obstacles like tunnels, climbing structures, and narrow passages can help keep a cat’s mind and body engaged, allowing them to hone their spatial awareness skills.

The study was published in the journal iScience.