This Mammal Can Detect Scents 6 Miles Away

28 February 2015

 - There are about 20,000 genes in mammals responsible for sense of smell. Of these, only about half are functional and the number falls even lower depending on the species.

Each species has a different number of genes dedicated to scent, and the genes code for olfactory receptors, which detect different smells. Inside your nose are about 6 million olfactory receptors that allow you to recognize thousands of different smells (although, some experts believe humans can smell closer to 1 trillion different odors, but have stopped noticing).

It sounds like a lot, until you realize that inside your dog’s nose there are up to 300 million such receptors. While you can detect certain odors in parts per billion, a dog can detect them in parts per trillion. This, too, sounds like a lot… until you compare it to other creatures in the animal kingdom.