In humans, smell is often viewed as an aesthetic sense, as a sense capable of eliciting enduring thoughts and memories. Smell, however, is the primal sense. It is the sense that affords most organisms the ability to detect food, predators, and mates.
There are many ways for organisms to probe the external world. Some smell it, others listen to it, many see it. Each species, therefore, lives in its own unique sensory world of which other species may be partially or totally unaware.