How Do Cats Drink Water With Their Tongues?

A cat lifts water into its mouth with a quick tongue movement. The tip curls backward and contacts the water; liquid sticks to its upper surface and rises in a short-lived column as the tongue withdraws. The cat then closes its mouth around part of that column. It is not carrying a little bowlful of water in a tongue-shaped spoon.

High-speed filming made this sequence visible. The familiar rapid lap is easier to understand as three connected events: contact, lift, and capture. The motion can be described confidently, while the detailed physics used to model it needs a little more qualification.

Follow One Lap From the Water to the Mouth

In their 2010 paper, Pedro Reis and colleagues filmed cats lapping and examined how the tongue and water moved together. Their observations show the following sequence:

The tip curls backward and meets the water. This brings the smooth upper surface near the tongue tip into contact with the liquid. “Upper” describes the surface of the tongue, even though the tip has curled back. Think of that surface label as staying with the tongue while it bends: curling changes which way the tip faces, not which surface is called upper. The contact to follow is at the tip, not inside a cup carried on the underside.
The tongue pulls away and water rises with it. Liquid adhering to the tip forms a column that briefly connects the tongue to the water below. At this stage the raised liquid is still connected to the bowl’s surface. As the tongue rises, the bridge stretches and narrows. The movement is not a sequence in which the tongue first fills a separate little container and then carries it upward.
The mouth closes around part of the column. In the original observations, the jaws typically closed before the column broke apart. The cat captures some of the lifted water, rather than collecting every drop. The jaw movement and the rising connection belong to the same sequence: the mouth intercepts liquid while that connection is still present. A picture of an extended tongue alone leaves out this capture step, just as a picture of a closed mouth leaves out how the water got there.

Picture a brief, stretching bridge of water between the tongue and the bowl. The tongue lifts one end, and the closing mouth catches part of the bridge. That is a verbal illustration of the filmed motion, not a rigid tube or a straw pulling water upward.

The shape changes continuously, so an ordinary still photograph cannot show the whole sequence.

The Backward Curl Does Not Make a Ladle

The tongue’s curled shape can make it tempting to imagine a scoop. But the important water connection in the original study is on the smooth upper surface near the tip. The rising column is lifted as the tongue retracts; the cat does not need a filled pouch on the underside to carry that water into its mouth.

Nor is the column being hauled up by the rough spines that give a cat’s tongue its sandpapery feel. The 2010 paper describes the tip involved in this contact as free of those filiform papillae. Our separate guide explains why the rest of the tongue feels rough; that anatomy should not be confused with the mechanism that lifts the water.

There is also a useful correction to the popular description that a cat “never dips” its tongue. In later primary research by A. W. Crompton and Catherine Musinsky, footage of one cat lapping milk showed the tip briefly entering the liquid. That small observation is enough to rule out “never,” but not to tell us how often every cat does it. The column-lifting sequence remains the central point.

Why the Water Keeps Rising for a Moment

The moving tongue sets the attached water in motion. Water that is already moving upward does not instantly stop when the tongue withdraws; at the same time, gravity acts downward. The original researchers modeled the main column behavior as a competition between inertia and gravity.

Here, inertia means the tendency of moving liquid to continue moving. It is not a separate upward pulling force supplied by the cat, and the cat does not have to understand the physics to lap.

To investigate the motion, the researchers also used a computer-controlled wettable glass disk as a simplified stand-in for the tongue tip. Lifting that disk from water produced a liquid column they could measure. The experiment helped isolate the water movement, but a disk is not a complete biological model of a cat’s tongue or mouth.

What the Glass Disk Helps Separate Out

Filming the cat answers what happens, but several things happen together: the tip bends, touches the liquid, withdraws, and returns toward a closing mouth. The disk experiment asks a narrower question: can a wettable surface lifted from water create the observed kind of rising liquid connection, and how does that connection change under controlled motion?

The researchers could control the disk’s upward movement and compare the columns produced with different disk sizes and lifting speeds. That made the physical relationships measurable without asking a cat to repeat a specially chosen movement on demand. In the experiment the column eventually narrowed and broke; part fell back into the water, while a drop remained attached beneath the disk.

That last detail is useful for picturing breakup. The water bridge does not vanish all at once, and saying it breaks does not mean that every trace of liquid instantly leaves the lifted surface. It also shows why the laboratory picture must be interpreted carefully: there is no closing mouth in the disk setup to capture the column as a cat does.

The experiment therefore contributes evidence about moving water, while the animal footage supplies the biological sequence. A simplified setup can make a mechanism easier to investigate without reproducing every feature of the animal. Agreement between part of the experiment and a model is useful evidence for that part of the explanation; it does not establish every proposed detail of a cat’s drinking behavior.

The cat’s closing jaws matter because the liquid connection is temporary. The observations show capture before breakup as the usual sequence in that study. They do not establish one exact ideal closing instant for every cat, or that a slightly later closure must deliver no water at all.

The Observed Motion and the Mathematical Model Are Different Claims

The physics explanation was discussed further after the original paper. In a 2011 technical comment, Michael Nauenberg challenged parts of the mathematical account, including its assumptions about pressure and how the column’s collapse time scales. He did not dispute that cats lift a liquid column and catch water from it.

The original authors’ published response defended their model using relationships measured in the laboratory experiment. They also acknowledged that the pressure behavior of the stretching column remained unresolved. The exchange should not be described as proving every detail of the model beyond question.

Surface tension is another reason to avoid an over-simple story. The response describes inertia and gravity as governing the earlier bulk motion to a first approximation, while surface tension contributes to the final narrowing and breakup of the column. Saying that surface tension has no role would lose that distinction.

For the everyday question, the useful division is straightforward: high-speed observations establish the contact–lift–capture sequence; the disk experiment and mathematical analysis help explain the moving water under simplified conditions. You do not need a universal lap rate, a fixed volume per lap, or a claim of perfect efficiency to understand how the tongue gets water into the mouth.

What This Explains About Your Cat’s Drinking

When your cat lowers its head to still water, a small movement at the tongue tip can repeatedly lift water for the mouth to catch. The motion may look like simple licking, but the short-lived liquid connection is doing an important part of the work.

That mechanism does not by itself tell you why a cat prefers a particular water source or whether its water intake meets its needs. For those separate questions, see why cats may drink from a tap and how to encourage ordinary access to drinking water. Neither bowl choice nor hydration can be settled just by counting visible laps.