Cats don't lap, they suck: New study reveals how our pets drink their milk without making a mess

By DAVID DERBYSHIRE

Cats use a particular method for sucking up milk rather than lapping, scentists have discovered,


It will come as no surprise to anyone who owns a cat.

But when it comes to lapping up milk, our feline friends have perfected the art of drinking with maximum elegance - and minimum effort.

Unlike dogs, who messily slurp water using their tongues as crude ladles, cats have evolved a sophisticated and super-efficient technique for sucking up liquids.

The same gravity-defying technique is used by every type of feline - from humble moggies to ferocious tigers.

Researchers made the discovery after studying high speed footage of domestic and zoo cats drinking from bowls.

It has long been known that when cats drink they extend their tongues towards the bowl - with the tip curled backwards like a capital J - so that the top of the tongue touches the liquid first.

But using high speed videos, American scientists found that the smooth tip of the tongues is the only part to touch the liquid.

The smooth tip brushes the surface of the liquid before the cat quickly withdraws its tongue. As it does, 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 to drink - while keeping its chin dry.

The study - published today in the respected journal Science - found that this column of liquid is created by the delicate balance between gravity which pulls the drink down and inertia, the tendency of liquid to carry on moving in the direction it has been pulled.

Domestic cats, jaguars, lions and tigers instinctively know how to lap in order to balance these two forces perfectly and when to close their mouths.

A domestic cat typically laps four times a second - with each lap sucking in 0.1 millilitres of milk or water, according to researchers at Massachusetts Institute of Technology, Virginia Tech and Princeton University.

However, big cats suck up liquid more slowly to keep the balance of gravity and inertia.

The study used high speed videos of cats - including the researchers own pets - along with tiger, lion and jaguar in American zoos.

They also gathered data by studying YouTube videos of big cats lapping.
The researchers also created a robotic version of a cat's tongue that moved up and down over a dish of water to identify the technique.

Dr Jeffrey Aristoff of Princeton's Department of Mechanical and Aerospace Engineering said: 'The amount of liquid available for the cat to capture each time it closes its mouth depends on the size and speed of the tongue.

'Our research suggests that the cat chooses the speed in order to maximize the amount of liquid ingested per lap,' said Dr Aristoff, a mathematician who studies liquid surfaces.

'This suggests that cats are smarter than many people think, at least when it comes to hydrodynamics.'

The study began when one of the scientists, Dr Roman Stocker of MIT, was watching his own cat Cutta Cutta lap milk.

'Science allows us to look at natural processes with a different eye and to understand how things work, even if that's figuring out how my cat laps his breakfast,' said Dr Stocker.

'It's a job, but also a passion, and this project for me was a high point in teamwork and creativity. We did it without any funding, without any graduate students, without much of the usual apparatus that science is done with nowadays.'


source: dailymail