We all have witnessed how dogs tend to greet each other. They sniff each other’s rear end! Can you imagine us doing that instead of a handshake? Why do they have that often embarrassing habit of greeting new doggie friends with their noses? There are many reasons why dogs do this. They want to find out each other’s gender, what they had for breakfast or if they’re sending out friendly vibes.

A dog’s sense of smell is its most powerful sense. We humans rely so much more on our sense of sight to learn about our world. A human nose has about 5 million odor receptors. Compare that to a hound dog’s 300 million receptors! Now you can understand why a dog can sniff out a single ounce of marijuana buried deep within a mountain of luggage filled with clothes scents and toiletries.

Our noses breathe air and odors in and out through our nostrils. A dog’s nose divides the air into two areas; the olfactory area and through the pharynx into the lungs. That way a dog can dedicate a portion of inspired air just to its sense of smell area of the brain. The dog is able to identify incoming odor molecules by their unique characteristics and send the signal to the brain for deciphering. Our nostrils are designed so that we inhale and exhale, sending the aromas we encounter out as soon as they come in. Dogs have slits in their nostrils that let exhaled air aerodynamically push new scents into the nose. These specially designed nostrils allow a dog to sniff in a more continuous, efficient way. A dog’s nostrils can also move independently which lets them know which direction a smell is coming from. That is why you will see a dog that is following a scent move its head from side to side. And, unlike us, dogs have a unique scent detecting organ that can recognize pheromones which are unique to each animal species.

Finally, a dog’s wet nose aids in its sense of smell. By having a damp nose, the mucus can trap dissipating odors in the air. Dogs will lick their noses which allows them to taste the chemicals in the odor which goes to another olfactory organ via the mouth to be analyzed by the dog’s brain.

So the next time you’re wondering about your pet’s odd habit of leg and butt sniffing, you’ll know why. Only the nose knows!