http://www.sciencemag.org/cgi/content/abstract/science.1195421
How Cats Lap: Water Uptake by Felis catus
Pedro M. Reis,1,2,* Sunghwan Jung,3,* Jeffrey M. Aristoff,4,* Roman Stocker1,*,
Animals have developed a range of drinking strategies depending on physiological and environmental constraints. Vertebrates with incomplete cheeks use their tongue to drink; the most common example is the lapping of cats and dogs. We show that the domestic cat (Felis catus) laps by a subtle mechanism based on water adhesion to the dorsal side of the tongue. A combined experimental and theoretical analysis reveals that Felis catus exploits fluid inertia to defeat gravity and pull liquid into the mouth. This competition between inertia and gravity sets the lapping frequency and yields a prediction for the dependence of frequency on animal mass. Measurements of lapping frequency across the family Felidae support this prediction, which suggests that the lapping mechanism is conserved among felines.
1 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
2 Department of Mechanical Engineering, MIT, Cambridge, MA 02139, USA.
3 Department of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
4 Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA.
How Cats Lap: Water Uptake by Felis catus
Pedro M. Reis,1,2,* Sunghwan Jung,3,* Jeffrey M. Aristoff,4,* Roman Stocker1,*,
Animals have developed a range of drinking strategies depending on physiological and environmental constraints. Vertebrates with incomplete cheeks use their tongue to drink; the most common example is the lapping of cats and dogs. We show that the domestic cat (Felis catus) laps by a subtle mechanism based on water adhesion to the dorsal side of the tongue. A combined experimental and theoretical analysis reveals that Felis catus exploits fluid inertia to defeat gravity and pull liquid into the mouth. This competition between inertia and gravity sets the lapping frequency and yields a prediction for the dependence of frequency on animal mass. Measurements of lapping frequency across the family Felidae support this prediction, which suggests that the lapping mechanism is conserved among felines.
1 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
2 Department of Mechanical Engineering, MIT, Cambridge, MA 02139, USA.
3 Department of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
4 Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA.
