Here is a fascinating study of the mechanism of cats’ tongues while drinking.
You gotta love these wacky MIT profs. Actually, quite an interesting story.
It’s bizarrely fascinating, isn’t it? I was watching my cat drink this evening, trying to see this effect. I wasn’t very successful, since she’d stop drinking as soon as I got close enough to actually see her tongue well enough!
Try binoculars 
I don’t have binoculars! So I’ll just have to move the water bowls to a spot where I can actually see them while I’m in the kitchen. Right now they are in a corner near the oven, so there aren’t any good lines of sight. 
Does this mechanism apply to bowls and everything else, or do they do something else when drinking from a faucet?
Hm, and I always believed what I read about the sandpaper-like prongs on a cat’s tongue acting like a sponge and taking water (or whatever) into the cat’s mouth. So that was wrong all this time?
Afraid so.
As I recall, it was not all that many years ago when it was first established the way their tongues worked. I seem to remember somebody filmed a cat at high speed to result in a slow-motion film, and all were astonished to find the tongue curling backward.
Now that I watch my cats,I can just barely see it.
The article compares it to dogs, which they say use their tongues as a ladle to scoop up water. This is wrong. I have seen high-speed camera views of dogs drinking. The spoon-like end of the dog’s tongue thrusts down into the water, producing an upward spurt of water, which the return stroke brings to the throat. It’s very similar to cat drinking.
It pretty hard to believe that nobody knew this before now.
This might explain why my aging cat would get a wet mouth after drinking. Her timing may have been off.
Further proof that cats are in fact aliens possessed of advanced scientific understanding. Let’s just be grateful that they are benevolent overlords.
Looks like this doggie has quite a bit in his tongue ladle… as well as *incidentally *catching some of the upward spurt of liquid. I had no idea dogs’ tongues curled backward like that when they drank.
CLEARLY, dogs learned this from cats but did not understand the scientific principle behind it and therefore mimicked it imperfectly.
My thesis stands. 