Discerning Dogs

Anatomical and physiological properties make dogs talented super-sniffers.

How much information do we perceive with our eyes? It is 80%. Just as sight is important for humans, smell is very important for dogs. Why is smell important? (Anybody knows someone who has temporarily lost smell because of COVID-19?). Do you know anyone in your class who has proven to be a talented sniffer? Maybe one of you can become an aromatherapist or food scientist? Let’s see how well dogs can smell.

1. Prepare three samples of natural scents, for example, putting cinnamon, lavender and dried mushrooms in separate bowls with a lid.
2. Ask pupils to stand 15 meters away and uncover one of the samples. Can they identify the smell inside each bowl?
3. Invite pupils to gradually come closer, until the first pupil identifies a smell. How close did they need to come to identify the smell? Alternatively, without talking, when a pupil thinks they know the smell, ask them to write the name of the smell on a slip of paper and leave it face down on the place they identified the smell.

You can repeat the experiment two more times with a different sample smell each time.

Explain to pupils why the distance of 15 meters was used. It is because a dog would have recognized the smell from this distance.

How come dogs are so good at identifying smells?

Simple explanation 

Whenever a dog is taken for a walk, it wants to stop and sniff everything. This is because dogs’ sense of smell is the most important sense for survival. They have approximately 15 times as many sensory receptors in their nasal cavity as humans, and the area of the canine brain devoted to odour analysis is also many times larger than the comparable part of the human brain. Over evolutionary time, dogs have become super-sniffers.

More detailed explanation

Dogs are very talented sniffers. When they sniff, some of the air they take in enters the olfactory centre in their brain. This brain area is much larger compared to humans. As a result, dogs have about 15 times more cells to perceive smells than we do. This and other adaptations allow the dog to have a remarkable sense of smell. In an experiment to find people buried by an avalanche, it took rescuers with magnetic probes 23 minutes to discover the bodies. One well-trained mountain rescue dog completed the task in 3 minutes. 

What if a dog’s sniffing superpower is mimicked in a new technology that could replace detection dogs trained to detect substances such as explosives, illegal drugs or life-threatening health conditions? 

Excellent smell is a dog’s superpower. However, having enough trained dogs for lots of situations is expensive and time-consuming. Moreover, dogs can become tired or bored. Scientists in the field of biomimicry explore possibilities to transfer successful 'sniffing' strategies of dogs to new technologies that are more reliable than dogs and capable of improving human life, such as by detecting explosives or health problems. 

Researchers mimicked the sniffing strategy of dogs to improve today’s devices for detecting explosives. When the researchers mimicked the nostril shape and breathing pattern of dogs in a device for detecting bombs, the dog-inspired device was 16 times better at detecting bombs than previous devices. The team of experts hopes that lessons learned from dogs will lead to new generations of technology for better detecting explosives, narcotics, chemical or biological pathogens, and even cancer. 

Some STEAM opportunities include:

• Observing and raising questions about how different animals adapt.
• Analyse advantage and disadvantage of different adaptations/behaviours.
• Asking questions and making observations.
• Carrying out simple tests.
• Making predictions.
• Using scientific evidence to answer a question.
• Apply learning to real world problems.

This video explains how a 3D printed dog nose improves the detection of explosives (watch here).

Dogs can use their super-sniffing skills to detect disease (find out more).

Watch this video explaining the biological strategy behind dogs smelling abilities (watch here).

Learn about the special skills of detection dogs (find out more).

Six ways smells influence your everyday life (find out more).