When we were little, we used to be said, "The dog must have changed when he ate his nose." Indeed, the dog has a sensitive nose that most animals don't have, and even cats have to give it three points. But you know who's the smartest guy in the dog world? Dog.
Our common dogs, drug dogs and guide dogs all have a good sense of smell, which is also a prerequisite for helping humanity carry out its tasks. However, when selecting such dogs, the sense of smell, while important, is not the full measure of the criteria. For dogs, agile hands and loyal character are as important as a sensitive sense of smell. And guide dogs, very high IQ and gentleness, are even more important than sensitive smell. So if it's a single smell, they're not champions.

The flying dog.
The dog's smell champion is a bloodhound from Belgium. Although IQ is low (74th place), tracing is beyond the reach of dogs. Not only does he have a sense of smell, but he is also an old man. He is one of the oldest hounds in the world to be raised by humans. In Belgium, he is regarded as a nobleman among dogs, who has long been favoured by the Belgian monarchy and regarded as a national dog.

Bloodhound.
So, how sensitive is the nose of a bloodhound? Bloodhounds can be used in early court to identify suspects because their noses are so accurate. In order to preserve its talent, the British, who love pet breeding, have improved their bloodhounds, which are now even stronger.

United Kingdom
According to scientific experiments, bloodhounds can recognize the smell of up to 14 days ago, and even today he is the favorite of European police officers. Its IQ and tracing capabilities are also paramount. The farthest traceable record is now as high as 220 kilometres, and this alarming record is maintained by bloodhounds. In other words, you did a crime in Beijing, and even if you went to Shiki's house, a bloodhound would bring you back.
Bloodhounds appear to be natural police officers who, in order to track down a scent, can stay awake for days, indomitable and ashamed of themselves. From its name, we can see the light of the bloodhound. It's just that they're too expensive to use in royal cases.
Bloodhounds, like bulldogs and hobbies, have a less beautiful face. The wrinkles on his face and the horns of his mouth, which were pulled down, and the angles of his eyes, which were not bent, all seemed unhappy, unknown and thought that someone owed him money. At the same time, this expression makes people think that he is weak and unspirited. But we can't look at the dog by our own standards, so confused by its appearance. This guy's very lively. He met the master and jumped. In the grass, it can even catch rabbits. How else can it be called a hound?
The dog's world is full of amazing things, and it's amazing that the bloodhounds have such a powerful sense of smell as our usual most common playmate. So don't underestimate any of the dogs around you, of course, and so do people, and maybe it's got some deep-seated technology.