This is going to make your weekend so much better. You'll no longer be plagued by uncertainty about the cat-milk-lap conundrum.
And you can thank Roman Stocker. He's an MIT guy. An expert in "fluid mechanics." His cat, Cutta Cutta, is the central character in the solving of this mystery. Roman would watch Cutta Cutta have breakfast each morning. Eventually he decided to apply his fluid mechanics expertise. This is what he found:
While dogs use their tongues to scoop up liquid, the cat's tongue makes only the briefest contact with the liquid's surface, before quickly retracting to pull a thin column of milk into the mouth.
The act of lapping is judged so perfectly the cat catches the milk in its mouth before gravity overcomes the liquid's inertia inducing it to fall back into the bowl.
Turns out the speed of the lap depends on the size of the cat:
High-speed video revealed that domestic cats average about four laps per second, with each lap bringing 0.1 millilitres of liquid into the mouth. Larger cats draw up thicker columns of liquid and so can afford to lap more slowly.
"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 maximise the amount of liquid ingested per lap," said Jeffrey Aristoff, a co-author on the study. "Cats are smarter than people think, at least when it comes to hydrodynamics."
Editor's note: Video has been updated.