How Do Dogs Use Smell?
Anyone who owns a dog has probably noticed now much time dogs spend sniffing and smelling the world around them. People have around six million olfactory receptors that analyze and identify good scents like perfume and gross scents like garbage. Dogs have up to 300 million olfactory receptors depending on the breed, which means that dogs are much more aware of smells than people are. Dogs use their sense of smell to find out about their environment, and they also enjoy taking the time to sniff and smell the world.
Why Are Noses Important to Dogs?
Although dogs seem to enjoy sniffing around, their noses are also very important for their survival. Like humans depend on eyesight for survival, dogs depend on their sense of smell. Dogs use more brain power for smelling than humans do, so it's not surprising that the area of a dog's brain that analyzes odors is up to 40 times bigger than the same area in a human's brain. Researchers estimate that dogs can smell between 1,000 and 10,000 times better than humans can.
Do Noses Talk?
Of course, dogs don't talk at all, especially with their noses. But dogs do communicate with their noses. Dogs can learn about other dogs by smelling them. Chemical aromas emitted by dogs tell other dogs what gender they are, if they're happy or sad, and what they like to eat. Dogs can also tell if another dog is healthy or sick and even if a female is pregnant by sniffing. Even if a dog hasn't seen another dog in many years, dogs can remember and identify other dogs by smell. Dogs will also be able to remember if another dog was dominant or submissive. Dogs can smell to learn about where other dogs were, what they ate, and what they did when they were away. If a dog gets lost, it can use its sense of smell like a compass to determine the way to go. Dogs also use their sense of smell to identify humans. Humans release adrenaline when they're scared or stressed, and dogs can sense adrenaline, too.
Why Do Dogs Smell Better Than Humans?
Dogs have something called Jacobson's organ, which is located inside the nasal cavity behind their upper teeth and on the opening of the roof of the mouth. If you ever see a dog curl its lips and flare its nostrils, it's activating the Jacobson's organ. Jacobson's organ increases a dog's ability to smell, and it has nerves that connect to the brain. Jacobson's organ allows dogs to detect substances that don't even have a scent to us. Jacobson's organ also helps dogs find mates. Using this organ, a dog can identify a dog of the opposite gender and also tell whether the dog is available for breeding. The organ also helps tiny puppies identify their mother so they can nurse.
In addition to Jacobson's organ, dog noses also have a few special quirks that make them more effective for smelling. First, dog nostrils can move independently of each other, so dogs can zero in on smells from any direction. Dogs also inhale through their large nostrils and exhale through tiny slits on either side of the nose, which helps scents circulate better for identification. Dogs' long snouts are also not an accident. The extra length of the snout humidifies and filters air so scent receptors work more effectively.
Why Do Dogs Have Wet Noses?
You may have heard that healthy dogs have wet noses. Dog noses work best when they're wet because the moisture helps to capture scent particles better. Dogs will even lick their noses if they become dry because they instinctively know that their noses work better when they're wet.