[music] [sniffing] There are noses and then, there are noses. And for sense of smell, the biggest is one of the best. Elephants use their noses for lots of things — finding mates, identifying family members, and probably most important, finding food. They’re good. They can find food very far away. But how good? To find out, researchers set up two experiments. To test smell at close range, they used two buckets. One had a plant that elephants enjoy and the other, a plant that smelled similar, but that elephants don’t like. The elephants easily detected the subtle differences between the two plants by smell alone. Then the researchers tried the same kind of test on a larger scale. They built an outdoor elephant-size version of the classic Y maze. Think laboratory mice sniffing for cheese. This was a more difficult problem. Sniff out the subtle difference between two similar plants at a distance — no problem for the elephants. Now, it may seem obvious that elephants can sniff out the foods that they like, but the differences between these plants are very subtle, and the plants are far away. “We can smell when our neighbor puts on the steak on the barbecue next door. They’re doing this throughout their entire environment, across multiple spatial scales, for things that don’t smell very strongly.” It turns out elephants are actually smell champions. Like other mammals, including humans, they have scent receptors that register molecules in air they inhale. The brain’s olfactory bulb picks up signals from those receptors. Elephants have more scent receptors and a bigger olfactory bulb than any other mammal. And there’s that trunk, which serves as a movable smell antenna, which can go under a log or into the wind. Their noses are so good that they help them avoid minefields in Angola. In fact, tests showed that they can detect TNT. [bell ringing] And one study showed that the elephants could use scent clues alone to detect the difference between two Kenyan tribes: the Maasai, who traditionally speared them, and the Kamba, who didn’t. Bomb detector, human sorter, food finder — that’s quite a nose.