How Cats Drink: On the Tip of the Tongue

Ever wondered how cats manage to drink so neatly and effortlessly with such small tongues? We all know how dogs do it; their sloppy big tongues lap up water louder than Grandpa Joe slurps hot tea from a cup. So do cats just employ similar tactics with more grace?

Last week, four highly qualified engineers revealed the feline's best-kept secret by using high-speed photography and a robot to mimic the cat's tongue. It turns out their method is a lot more complicated than one would think. Because cats lap four times per second, the human eye cannot detect the movement, which is why it's remained a mystery until now.

The engineers reported in the Thursday issue of Science that the process is governed by inertia and gravity. In other words, the cat darts its tongue, curving the upper side downward to let the tip lightly touch the water. It then pulls its tongue up quickly to draw a column of water behind it. At this moment gravity starts to pull the water downward but by that stage the cat has already closed its mouth over the stream of water and swallowed it.

But the description isn't the most complicated part. The engineers calculated things like the 'Froude number' and aspect ratio to figure out how fast a cat needs to lap in order to get the greatest amount of water into its mouth. They then worked on a formula to determine whether bigger cats lapped at a different speed. Simple really: the lapping frequency is the weight of the cat species, raised to the power of minus one-sixth and multiplied by 4.6...duh!

They even videotaped lions, leopards, jaguars and ocelots, to test their formula. All these big cats lapped at the speeds predicted by the engineers.

Way to go science!

For us lay people, it's pretty fun to watch these slow-mo videos of cats and a dog lapping it up.

Here is the cool cat from the study, Cutta Cutta, uploaded by the MITNews Office.

A longer video, courtesy of the WhiskasNetwork.

And here's a dog, just for comparison, from DiscoveryNetworks.

Image Source: Flickr user macinate