It is worth wondering, we mean, does ice even smell?
Water doesn't tend to smell of much, so surely neither does ice. And if something has no smell, then how would a dog detect it? Now, ice is cold, so can dogs smell the 'cold' part of the ice and detect a temperature gradient? Or could it be that ice does have an oh-so subtle smell that we nose-blind humans simply can't detect. Lets find out.
Signs a Dog is Following a Scent
You may be used to seeing a pet dog sniffing around, nose down in the yard. However, a trained tracking dog moves in a much more focused way and actually has distinct body language depending on how close to the scent they are.
When the object is a distance away, the dog moves quickly, often in a zig-zag pattern. They take lots of shallow sniffs as they move. This combination of movement and rapid sniffing helps them work out in which direction the scent is strongest, so they can move towards it.
Once the smell gets stronger and it's necessary to pinpoint the location, the dog slows down. Their sniffing pattern changes such that they take fewer but deeper breaths. This moves air into a different part of the nose where it is processed and analysed. The dog can draw down information such as how fresh the scent is and who left it.
As the dog closes in still further, they often offer a distinctive physical reaction, such as lifting a paw to point, so their handler can identify where the object is.
- Head tilting
- Walking in a zig-zagging path
- Tail up and alert
- Nose to the ground
- Rapid shallow sniffing, followed by fewer, deeper breaths.
The History of Dogs Using Their Sense of Smell
Detection dogs are increasingly used to help security at places like airports. But these clever dogs aren't always sniffing for explosives. Dogs can be trained to sniff out pretty much anything, including currency, smuggled food, and even stowaways. Indeed, some amazing dogs are so gifted they can warn diabetic owners that their blood sugar levels are falling dangerously low, or even detect cancer.
These are all examples of the modern use of a dog's natural ability to follow a scent. Indeed, this natural talent is one of the reasons that dogs first became domesticated, back all those millenia ago. A good tracker dog could hunt down prey and make the difference between eating or not eating. Add into that the companionship a dog provides, along with guarding skills, and it's little wonder dogs and man became a perfect match.
The idea of formally trained sniffer dogs is a relatively recent thing, dating back to World War II. The first recognized detection dogs were trained by the US military to sniff out unexploded landmines in North Africa. Those heroic animals saved many lives and it set a train of thought rolling about the uses to which a dog's nose could be put.
The Science of Dogs Smelling Ice
It may well be that ice does have a smell, because of its nature and its physical construction. Ice is made from water, which has low levels of minerals dissolved in it. Each of those minerals has a barely-detectable (to the human nose) scent signature. But in ice, those same minerals are trapped. It's possible that as the ice-ages, those molecules slowly rise up to the surface to be given off as an odor.
Also, for the ice blocks in the freezer, there's a more mundane explanation as to why they might smell slightly. The ice absorbs the odor of the food items in the freezer. Hence, they take on some of the scent characteristics of the other things in the cooler.
Of course, the other thing about ice is that it melts. So if you had a sniffer dog trained to detect ice, they would need to be a speedy worker or the very thing they were trained to detect might simply cease to exist! How frustrating for the dog.
Training a Dog to Detect a Specific Substance
However, it's relatively straightforward to teach a dog to sniff out more stable substances, and here's how.
First, you get the dog interested in a game, such as "tug." You get them really keen on the game, encouraging them with praise and making it heaps of fun.
Then, take a clean towel and use this for the tug toy. Because it's clean, it doesn't have a distinctive scent and it is like a blank canvas. Play tug with the towel and the dog, so they understand this is a toy.
Now, introduce a second towel, but this time, it has the odor of the object you want the dog to detect on it. Place it side by side with the clean towel. If the dog selects the clean towel for a game of tug, ignore them. But if they pick up the odor-marked towel, get excited and make sure they have a great game. This way, the dog starts to learn that a particular smell means they get a good game.
Make things slightly more difficult but placing the odor-impregnated towel on the other side of the room. Encourage the dog to find it, in a doggy game of 'hotter' or 'colder' using the excitement in your voice to convey the message. Again, once the dog goes to the correct towel, reward them with a game.
The next step is to widen the choice by offering several towels, only one of which is the target, and hiding them around the room. When the dog chooses the correct towel, give them lots of praise and a game of tug.
The final step is to put this behavior on cue, with words such as "Find" or "Detect", which tells them it's time to sniff for that special scent.