This website is no longer actively maintained
Some material and features may be unavailable

The Daily Need

Photo: Lapping it up

Photo: Dave Dugdale /

People with cats are well aware that they do things in their own special way. Now, researchers have discovered that their tongues are no different. One morning, while sharing breakfast with his cat Cutta Cutta, biophysicist Roman Stocker of the Massachusetts Institute of Technology in Cambridge began to doubt the assumption that cats, like dogs, lap up water by curling their tongues into the shape of a ladle and scooping up the liquid.

With the help of high-speed cameras and some local shelter cats, Stocker and his team discovered that, unlike dogs, cats’ tongues don’t penetrate the surface of the water when drinking. Instead, the tip of the cats tongue rests on the waters surface. The water sticks to the tongue and when the cat draws its tongue back into its mouth, the water is pulled upward in a column. When the cat closes its mouth, it breaks the column. The lapping balances the water’s inertia (as it moves upward along with the tongue) and the pull of gravity (as it falls back into the bowl). Cats know how to lap faster than gravity can overtake inertia. The team’s findings were reported yesterday at

So: if our cats can casually master the physics behind gravity versus inertia, why do they still insist on practicing this impressive skill by drinking from the toilet? Because they can, I guess.

  • thumb
    Reunited after the explosions
    An unidentified Boston Marathon runner, center, is reunited with loved ones near Copley Square.
  • thumb
    Obama boards the Rosa Parks bus
    President Barack Obama sits on the famed Rosa Parks bus at the Henry Ford Museum.
  • thumb
    Puppet theater
    After disappointing results in the Mississippi and Alabama primaries this week, former Speaker of the House Newt Gingrich vowed that his campaign would continue.


  • rick

    another use for a hairy tongue

  • Dugdale

    Karen, I am so glad that you liked my Flickr photo so much that you included it on this page. I enjoy when people use my photos, but as I noted on Flickr below each photo I let people use my photos on the condition that they provide me credit to my site. Please add my link when you can. Thanks, Dave

  • Karen at Need to Know

    You are absolutely right Dave! I have included your link into the photo caption, and also included a link to you on the “blown up” version of the photo. We want to make sure proper credit is always given. Thank you so much for providing a creative commons license on your beautiful photo!

  • Dugdale

    Thanks, I really appreciate it.

    Also thanks for using my photo, I love to see them viewed by as many people
    as possible.