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Why do dogs have a better sense of smell than people? 

Asked By

Austin Henyan

School: Port Dickinson Elementary School, CVCSD
Grade: 2
Teacher: Mrs. Shelepak
Hobbies/Interests: Football, basketball, baseball & reading
Career Interest: NFL player

Answered By

Debbie Dittrich

Senior Research Support Specialist
I work in the Integrated Electronics Engineering Center at Binghamton University and am responsible for teardown analysis of cell phones. I am a docent at the Binghamton Zoo. I also enjoy gardening and outdoor photography. 

Animals have all kinds of remarkable adaptations. Some might even seem like superpowers to us. Dogs, for instance, can use their sense of smell to locate missing people, or sniff out explosives and drugs. There are even dogs that are capable of alerting a diabetic owner when their blood sugar is getting too low.

One trick that makes a dog’s sense of smell superior to our own is a small flap of tissue that divides inhaled air into two paths. Most of the air flows to the lungs (as does all of our breath), but about twelve percent goes directly to the dog’s olfactory region. This region is located in the back of the nose and has a surface area of about thirty square inches (as opposed to one square inch for humans). A dog can have 100 million to 300 million olfactory receptors in this region, which filter scents from the air. Humans have only 5 million of these receptors. When the dog exhales, the air leaves through slits in the sides of its nose, so as not to interfere with new scents waiting to be inhaled. Dogs can also wiggle each nostril independently, allowing them to determine the direction an odor is coming from.

Once the olfactory cells have trapped odors, electrical signals are sent to the brain for interpretation. Here again, the dog has an advantage over humans, as the area of the brain dedicated to smelling is much larger in the dog’s brain.

DNA studies suggest that dogs are related to gray wolves. For a wolf, survival depends on being able to find prey, locate mates and pack members, and avoid predators. Even though our pampered pets no longer face these challenges, you can see why they are such remarkable sniffers!

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