What trait distinguishes animals with a good sense of smell?

The main sign of a good sense of smell in animals is the moisture in the nose. Depending on the quality of smell, the animal’s nose will be either wet or dry. The regularity is that the higher the level of the animal’s sense of smell, the wetter its nose will be. For example, a dog’s nose is many times wetter than a cat’s. Why does nasal moisture matter at all? The moisture in the nose helps the animal to determine the direction of the wind, and accordingly, the source of the smell.