As I have mentioned before, dog noses are the best noses ever. They can sniff out all sorts of important stuff, such as food, drugs, insects, bombs, dead bodies, trails, game, criminals, and cancer. And the reason dog noses are so good at doing this is because of the way they are made.
First of all, a dog's nose is usually wet, and this is a good thing because the little tiny pieces of scent, which are called molecules, stick to a wet nose. So when the dog goes around sniffing the ground or somebody's luggage or somebody's crotch, the scent molecules end up on the dog's nose. And after that, they go inside the nose, where there is a whole bunch of sticky mucous. The mucous is in these folds of skin called membranes, and there are lots of mucous membranes inside a dog's nose. In fact, if you took all of a dog's membranes and spread them out flat, they would be as big as the state of North Dakota. Hahahaha! I'm just kidding! Actually, they would only be as big as a handkerchief, but that's still pretty big. Especially when you know that the mucous membranes inside a person's nose would only be the size of a postage stamp.
So anyway, when the scent molecules get inside the nose, they go into these spaces that have all these membranes with scent receptors. A dog has about 200 million of these receptor thingies, and a person only has about 5 million. This is why dogs can smell stuff soooooo much better than people can.
The scent receptors are connected to nerves that go to the brain, and the brain sorts everything out and makes sense of what the dog is smelling. So for example if a dog sniffs a spot where a cat has been, the dog can tell that a cat was there, whether it was male or female, how long ago it was there, and which way it was heading. Maybe a dog can learn even more than that from a scent, but I do not want to betray my fellow canines by giving away all our secrets!
Okay, and here's another interesting thing about dog noses. Dogs inhale through the central nasal tubes, but then exhale through the slits in the sides of the nose. This makes the air go outward and sideways when it is exhaled, and that stirs up more scent molecules. Clever, huh? And dogs with long ears, like bloodhounds and bassets, stir up scents by dragging their ears through the grass.
Another thing you might be interested to know is that dogs with long noses can detect smells better than dogs with short noses. This is because there is more of that mucous membrane stuff inside a long nose than there is inside a short nose.
Anyway, I'm glad I have a fairly long nose and that I can smell all sorts of fascinating things. Dogs get a lot of pleasure from life by smelling things, which is something that humans don't really understand. If humans really "got it" when it comes to noses, they would sniff each other's butts like dogs do when they meet, instead of just shaking hands.
