Anyone who has ever watched a dog drink—and witnessed the often messy aftermath—has wondered just what’s happening with all that tongue lapping and lip smacking. Well, here’s your answer. By employing super high-speed cameras, researchers discovered that dogs form their tongues into an inverted ladle, scooping water into the mouth. Case solved, right?
Not so fast. It turns out that the “tongue ladle” doesn’t actually do a very good job of conveying water into the dog’s mouth (which you can see in the video above). The real answer to this age-old question is much stranger:
The tongue, it turns out, is not a ladle, but a sticky whip. A dog will extend — no, that’s too polite a word — the dog will thrust its tongue into the water and then whip it back up, very, very fast. A stream of water attaches to and follows the tongue upward (adhesion and cohesion) — but only for a fraction of a second. Then gravity kicks in. The rising stream of water loses its upward momentum, and just as it’s about to fall back into the bowl, at exactly the point where gravity is about to win, the dog snaps its mouth shut and swallows. Done. The motions are precise, even mathematical.
Fido is actually a mathematician!