It turns out that moles may have a more powerful sense of smell than we think.
According to new research, there are indications that moles can smell in stereo, which allows the mole to find its prey via smell.
A paper published in the journal Nature by Kenneth Catania, a professor of biological sciences at Vanderbilt University, shows that moles have been able to distinguish subtle differences in smells between their different nostrils.
Catania studied star-nosed moles in the 1990s and discovered that they could use the sense receptors on its nostrils to scan the tunnels for food.
In tjhis latest study, which focused on the Eastern mole, he found that this particular mole, which is blind, lacked the star-nosed moles receptors and can only hear low frequency sounds, were able to find food just as easily by following their noses.
Even when blocking the nostril, the mammals adjusted by simply heading in the direction of the scent registered by the open nostril.
Catania was skeptical entering the study, believing that the moles’ nostrils were too close together to be able to detect odor gradients.
But he soon became a believer.
“I expected the common mole, which is virtually blind and doesn’t have a very good sense of touch, to be a lot worse than the star-nosed mole,” he told Vanderbilt University’s newsletter. “So I was quite surprised when they turned out to be very good at locating prey. At the time, I figured that they must be using their sense of smell, but I didn’t pursue the matter.”
His experiment had the moles try to find their food, which was pieces of earthworm, around a radial arena, changing the location of the food everytime. Even with their nostrils blocked, the moles always found their way to the right food well.
“It was amazing. They found the food in less than five seconds and went directly to the right food well almost every time,” Catania said. “They have a hyper-sensitive sense of smell.”
Overall, Catania finds that his study shows that the Eastern mole can “make use of bilateral chemosensory cues combined with serial sampling to localize odorants and offer insights into the relative contribution of each strategy during different stages of natural search behaviours.”