How Do Cats Drink Water With Their Tongue?

Kitty taking a drink is actually a spectacular display of fluid mechanics.

Kitty taking a drink is actually a spectacular display of fluid mechanics.

Have you ever watched Kitty drink water? You may think he curls his tongue and uses it like a cup, but the truth is a little more mind-blowing. Kitty is an efficient, water-drinking machine that took MIT engineers, high-speed photography and 3 ½ years to understand.

Too Fast for Human Eyes

Kitty can lap four times a second at a speed of three feet per second. At this speed, his lapping tongue is simply a blur to human eyes. This is why no one understood exactly how Kitty lapped his water until recently. Roman Stocker, a professor at MIT, was perplexed watching his own kitty, Cutta Cutta, lapping milk from a bowl. This lead him to recruit a team of MIT engineers to do a study to understand exactly what was going on when Kitty takes a drink.

Kitty's Scientific Genius

Cats can't create suction to drink the way humans do. Instead, Kitty uses fluid mechanics to efficiently lap up water from his dish. While dogs, somewhat messily, use their tongue kind of like a spoon lifting water into their mouths, Kitty's technique has a little more finesse. When Kitty's tongue heads toward the water, it moves in “J” shape, the tip flicking backwards onto the surface. Then he pulls his tongue at incredibly high speed back into his mouth causing a column of water to jet into his mouth following his tongue. At just the moment when gravity would pull the water back towards the dish by overcoming inertia, Kitty snaps his mouth shut effectively trapping the water.

Super Efficient

Stocker and his team decided to test the findings with a robot that mimicked the way Kitty drank water. It had a glass disk on the end of a piston that could pull water up the same way Kitty does. They wanted to see if they could determine the speed Kitty would have to lap to get the most to drink. When they plugged the information into some fancy equations, Stocker discovered something extraordinary; Kitty was already drinking at the speed that would allow him to get the biggest bang for his buck. Turns out, evolution did an excellent job equipping Kitty with the skills he needed to never go thirsty.

Big Cat Cousins

Stocker speculated that because his wild cousins, like tigers or leopards, have larger tongues they wouldn't have to lap as quickly to be equally effective. His research team at MIT took some videos of big cats having a drink at the zoo and used some videos that were uploaded online. They reviewed videos of a cheetah, bobcat, lion, tiger, jaguar, ocelot and leopard. Their hypothesis was spot on. The larger felines didn't have to drink as quickly as their domestic cousins to to get the same effect. Stocker's team might use the information to develop “soft robots” that can manipulate liquids in the lab. In the meantime, the results prove just how cool you already knew your kitty was.

 

Photo Credits

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