Humans and many other mammals see and hear in stereo. But what about smell?
"People have wondered for a long time whether smell has this component as well," said Kenneth C. Catania, a biologist at Vanderbilt University. Now he and colleagues report in the journal Nature Communications that common moles, which are blind, have the ability and use it to swiftly locate prey.
Dr. Catania created a chamber with food wells spaced around a semicircle and watched as moles detected the food. The chamber was sealed, so changes in air pressure would indicate that the animals were sniffing.
Moving their noses back and forth, the moles zeroed in on the food in less than five seconds.
Dr. Catania then blocked one of the moles' nostrils with a plastic tube. When the left nostril was blocked, the moles veered off to the right, and when the right was blocked, they veered to left. Although they were still able to find the food, it took them much longer.
To confirm that the moles use stereo sniffing, Dr. Catania put plastic tubes in both nostrils and then crossed them.
This confused the moles, causing them to think that food to their right was actually located to their left. But their response confirmed that the moles in fact use stereo sniffing, Dr. Catania said.
Previous research indicates that rats can smell in stereo, and there are suggestions that sharks and ants can, too.
"The jury is still out on how many animals can do this, and that will tell us how primitive this is," Dr. Catania said. "If only a few animals do it, then it may have evolved recently."
So can humans smell in stereo? Unlikely, he said.
This article originally appeared in The New York Times.