Thirsty cats

Watch these two videos and see what you notice...

Or watch in YouTube.

Or watch in YouTube.

The top video shows a dog drinking water. The bottom video shows a cat drinking milk. Both the videos are in super slow motion. What did you notice about the way the animals drank the liquids? Watch them again and concentrate on the tongue.

A dog drinking - look at the tongue (c) Randy Robertson

Dogs use their tongues like a spoon. They curl their tongue way back to form a ladle shape. They dip all of the 'ladle' into the water and scoop it out. Did you notice that the dog was much messier than the cat? The dog had water all over his chin!

 

Until recently, people didn't know how a cat drank without making a mess. Researchers investigated and found out that cats also curl their tongue backwards, but only a little bit. Only the tip of the tongue touches the liquid. Then the cat quickly draws its tongue back up to its mouth. A column of liquids forms between the cat's moving tongue and the liquid's surface. The cat closes its mouth, which pinches off the top of the column. This means the cat gets a nice drink whilst keeping its chin clean.

 

The cat has to know the exact moment to close its mouth around the liquid before gravity drags the liquid back to the bowl. The researchers showed that cats get the most liquid in each sip by lapping at the exact speed that balanced two forces: the inertia pulling water upward and the gravity pulling it back down. Maybe cats know more about physics than we do?

To find this out the researchers cleverly filmed one of their cats - the one in the video above - in slow motion. They found out that domestic cats drink very quickly - they can lap four times per second - and can drink around five tablespoons of liquid in a minute. Pretty impressive for an animal with a tiny tongue!

Lion drinking

The researchers also found that big cats drink in the same way, but slower. So a lion and tiger laps more slowly than a house cat. Do you think lions and tigers get more water in one lap because their tongues are bigger?

So, if you have a cat or a dog, why don't you watch the way it drinks? Check whether the scientists were right. If you're feeling adventurous you could try drinking like a dog or a cat. Try not to make too much mess!

For more information about the way cats drink, go to the Massachusetts Institute of Technology website.