Can Dogs Smell Through Walls?

We are all fully aware of just how powerful a dog’s nose actually is, and it’s amazing to see it when it’s in action. We know that a dog can smell an assigned scent through different materials, such as in water and for this reason, they are incredibly useful for investigative reasons. 

As we know that dogs can use their sense of smell in various contexts, we will take a look and see if dogs are able to smell through walls.

Dogs have amazing noses! When a smell catches their interest, there is little you can do to gain their attention back. This is even more the case with hound breeds like the Bloodhound and the Beagle. You have probably heard of dogs sniffing through suitcases - or even water, but have you ever hear of a dog being able to smell through a wall?

Yes, it's true, many dogs are able to smell through walls. Owners of an intact female are probably already aware of this, as any intact male in the area is likely able to tell where their girl is - even if she is inside!

Unless your dog has been trained to display certain signs when they catch a scent, you'll probably be able to notice basic behavioral signs when your dog smells something through a wall. They will often raise their ears, put their nose to the wall, and they may even lick the wall. It's not uncommon to see your dog's back hair on edge, as they become very alert, tensing their jaw and not moving away from the wall - obsessively sniffing and freezing.

Dogs have been used by humans for many years, as they have a natural smelling ability. They were used for detection reasons back in the 1940s. At that time, they were employed to sniff out mines and then in the 1970s, dogs began to help sniff out drugs and other illegal substances such as heroin, marijuana, explosives, and illegal money. Dogs have been working with law enforcement for a long time and have therefore been able to signal when they smell something of interest.

Support of dogs for law enforcement purposes then became a part of policing as we know it today. Dogs are now trained for scent detection reasons in various circumstances, and they have been taught to act in both aggressive and passive ways, depending on the situation. 

It is not uncommon to see dogs now being used for supporting security operations, search and rescue missions, detecting illegal substances and explosives, helping military staff, and chastising criminals. Detection dogs can now be seen regularly in places such as airports or at public events.

Historically, there was not much use for dogs' ancestors to smell through walls until domestication set in, and even then, it's not a natural ability that is overly warranted.

A dog has a lot more cilia (tiny nose hairs) than we do - they have approximately 100 per cell, where we would only have around 6. When it comes to brain structure, a dog’s brain is designed to rely on its sense of smell over any other sense. Even when the physiology is considered, a dog’s respiratory system has developed to be able to accurately analyze smells. The receptors in the nose and in a dog’s brain then work together to investigate a scent, and they also work together to make connections based on previous experiences.

We know that dogs can smell into a container, but they are not able to smell through something that is vacuum-sealed. When it comes to walls, we know that they are not vacuum-sealed and air can escape, which means odors are able to escape. It is, therefore, highly likely that under these circumstances, your dog can smell through a wall.

The material of the wall can also be a factor as to whether your dog is able to smell through it. For example, plasterboard is porous while glass is not. It then follows that a dog will be able to smell through a plasterboard wall, as it will contain small microscopic holes that allow odor to escape, and this odor will be able to be smelled by your dog. 

If a wall is made of glass or metal, it is, therefore, non-porous. A dog will not be able to sniff these odors in a glass or metal wall, as the environment is airtight. If any of the scent, however, has been left on the wall (such as when transferred via our hands), then a dog will be able to pick up on that scent.

As we know, a dog can be trained to smell out a specific scent. When it comes to training a dog, rewards for correct identification or positive reinforcement are the methods used. When it comes to training a dog for scent detection, it can take a few months. Dogs are taught to correctly identify a scent by association and are taught search patterns while being rewarded throughout the training procedure. 

When it comes to scent detection, the breeds of dogs that are commonly used are the Belgian Malinois, German Shepherds, and Labradors. The reason for this is because these breeds have a stable temperament, as well as having a robust drive when it comes to prey. These characteristics all enhance their motivations for searching. 

Additionally, it is important that a dog that is going to be trained is both mentally and physically capable to undertake what the training requires. Once you are confident that a dog has all these skills, then the dog is ready to begin training.

If you are training a dog to smell through a wall, you will need them to be able to identify the scent that you will hide behind the wall first. This will be done through play. Using a clean piece of material, you will need to play games such as tug of war with the dog. Slowly, you will need to hide the chosen scent in this piece of material. Once again, you will need to play tug of war with this material. 

Over time, the dog will learn to associate the smell of the material with playing tug of war. If you then place the chosen scent behind a wall and the dog can detect it, the dog will react in the same manner that they did when you played tug of war. Make sure that the wall that you choose to test this training on is porous so that scents can be released via the wall material.