What animal has the best sense of smell?
African elephants are thought to have the best sense of smell, with about 2,000 smell-receptor genes. Bears and bloodhounds also have extraordinary noses.
A 2014 study compared smell-receptor genes in 13 mammals and found that African elephants have about 2,000, around five times as many as humans and more than twice as many as dogs. Elephants can smell water from several kilometers away and distinguish between groups of people based on scent.
Bears also have an incredible sense of smell. A polar bear may be able to detect a seal from more than a kilometer away. Bloodhounds, with about 300 million scent receptors in their noses compared with about 6 million in humans, are so reliable that their tracking results have been used in court.
Smell in the sea and sky
Sharks can detect tiny amounts of blood in water, and salmon use smell to find their way back to the rivers where they hatched. Some moths can detect the scent of a mate several kilometers away. Turkey vultures can find dead animals by smell, even under forest cover.
Did You Know?
Humans can distinguish more smells than once thought. Some scientists estimate we can tell apart thousands or even millions of different odors.