How cats lap up milk so elegantly

WASHINGTON - A team of researchers think they have the answer to a mystery that has long puzzled cat lovers: exactly how do their feline friends lap up milk so elegantly?

Researchers at MIT, Virginia Tech and Princeton University analyzed the way domestic and big cats lap and found that felines of all sizes take advantage of a perfect balance between two physical forces.

It was known that when they lap, cats extend their tongues straight down toward the bowl with the tip of the tongue curled backwards like a capital “J” to form a ladle, so that the top surface of the tongue actually touches the liquid first.

But recent high-speed videos made by this team clearly revealed that the top surface of the cat’s tongue is the only surface to touch the liquid. Cats, unlike dogs, aren’t dipping their tongues into the liquid like ladles after all.

Instead, the cat’s lapping mechanism is far more subtle and elegant. The smooth tip of the tongue barely brushes the surface of the liquid before the cat rapidly draws its tongue back up. As it does so, a column of milk forms between the moving tongue and the liquid’s surface.

The cat then closes its mouth, pinching off the top of the column for a nice drink, while keeping its chin dry.

The liquid column, it turns out, is created by a delicate balance between gravity, which pulls the liquid back to the bowl, and inertia, which in physics, refers to the tendency of the liquid or any matter, to continue moving in a direction unless another force interferes.

The cat instinctively knows just how quickly to lap in order to balance these two forces, and just when to close its mouth. If it waits another fraction of a second, the force of gravity will overtake inertia, causing the column to break, the liquid to fall back into the bowl, and the cat’s tongue to come up empty.

While the domestic cat averages about four laps per second, with each lap bringing in about 0.1 milliliters of liquid, the big cats, such as tigers, know to slow down. They naturally lap more slowly to maintain the balance of gravity and inertia.

The results will be published in the November 11 online issue of the journal Science. (ANI)