‘Cats rule, dogs drool’ is a funny way to describe the difference. The dog has a cruder drinking technique than the cat. That’s what I claim! We know that cats are more sophisticated than dogs, don’t we?!
Research, at the Massachusetts Institute of Technology, Virginia Tech and Princeton University in the USA, has explained how cats get liquid into their mouths. It is a sophisticated technique evolved over eons, I suspect. The dog, in contrast, just grabs hold of it with their tongue and shovels it into their mouth 😉 .
For the cat, “sophisticated hydrodynamics” are employed – yes, it’s very scientific and shows how anatomically sophisticated the cat is whereas the dog slurps and splashes. In the video of the dog on this page it seems that he/she scoops up the water by cupping his tongue underneath (the opposite direction to what we would assume) whereas the cat does not employ cupping and scooping. For a cat, it is all about a balance between surface tension, inertia, gravity and hard science, which I am yet to fully understand 😉 .
The study shows that, when drinking, the cat’s slightly curled tongue is the only part of the tongue which touches the liquid. In fact it is the only part of the cat to touch the liquid. The tongue brushes the surface and as it does this a…
“column of fluid forms between the moving tongue and the liquid’s surface. The cat then closes its mouth, pinching off the top of the column to drink”.
Gravity pulls the liquid off the tongue (downwards) while inertia keeps it on the tongue as inertia creates a tendency for the liquid to carry on moving in the direction it has been pulled. It is a question of timing for the cat. If the cat delays in closing his mouth and drinking, gravity will pull the liquid off the tongue. In other words, gravity overtakes inertia if there is a delay. The video below is a slo-mo version of a cat’s tongue in action.
Whereas the dog, as mentioned, does it differently and more clumsily, if I may say so. The dog causes more mess because he drives his tongue onto the liquid with force. This causes a splash. Then dogs withdraw their tongues rapidly which forms a water column. It would seem inertia, gravity and surface tension also play a part but the dog also scoops up the water in the same way we do when we drink with our hands. This is a distinct departure from the more sophisticated, and dare I say it, more elegant cat technique.