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One little dog barely reaches a big dog's knee. They look nothing alike. So how do they know the other one is a dog too? The answer comes in two steps. From far away, they look. Up close, they sniff. First, the eyes. Scientists in France showed nine dogs faces on a computer screen.
Dogs of every breed, plus human faces and forty other kinds of animals. All nine dogs could pick out the dog faces, big or small, long hair or short. So just by looking, a dog can tell: that's a dog too.
But the eyes only say "dog." Which dog, boy or girl, happy or not — that's a job for the nose. A dog's nose has up to three hundred million little smell sensors. We have about six million. That's why when two dogs meet, they love to go sniff each other's rear end.
It's not rude. On each side of a dog's bottom is a tiny pouch that gives off a strong smell. That smell is like a business card. Every dog's is different. Scientists think the card says: boy or girl, healthy or not, what mood it's in, and what it's been eating.
One team took the smell apart and found sixty-four different chemicals, and boys and girls had different mixes. Above the roof of a dog's mouth is a small organ just for reading these signals. People have one too, but ours mostly doesn't work anymore. Sniff once, and next time they meet, it knows: oh, it's you.
So butt-sniffing isn't picking a fight. It's saying hello. Like people shaking hands and swapping cards. The eyes tell it: that's a dog. The nose tells it: who that is. Next time your dog goes to sniff another dog, don't rush to pull it away. It's reading a business card.
What other strange dog greetings have you seen? Tell us in the comments.
From far away, the eyes say “that's a dog.” Up close, the nose says “who.”
A little dog may barely reach a big dog's knee. They look nothing alike, yet they still know each other as dogs.
On each side of a dog's bottom is a tiny pouch that gives off a strong smell. Every dog's is different, like a business card.
In 2023, scientists took this smell apart and found 64 chemicals, with different mixes in males and females. What else the card says is still being decoded.
Above the roof of a dog's mouth is a small organ just for reading these signals. People have one too, but ours mostly doesn't work anymore.
All that circling isn't stalling. Before squatting, a dog runs four checks, and often lines up north to south.
Common, but not every dog does it. Three research-backed reasons, three vet explanations not yet studied, and when following can signal separation anxiety.
Most zoo animals outlive their wild cousins. But is a longer life a happier one? It depends on the animal and the zoo, plus three things to look for on your next visit.
There's no official champion, but there is a pattern: the more meat an animal eats, the worse its poop usually smells. Then there are otters.