Star-nosed moles are nature’s speed-eating champions

How else are they weird? Let us count the ways

star-nosed mole
Ken Catania

It looks like a fuzzy alien with tentacles coming out of its face. But as strange as the star-nosed mole appears, it's actually a pretty standard Earth-dweller, appearing in wetlands and swamps along the east coast of North America.

“They can be hard to find. They're not uncommon, but they are uncommonly seen," explains biologist Ken Catania. But behind their reticent nature is an animal with some pretty amazing abilities. “It's an incredible animal in almost every way I can imagine,” Catania says.

Catania gave a talk on some of the more incredible aspects of this animal's anatomy on Sunday at the Experimental Biology conference in Chicago. Popular Science spoke to him on Friday before he drove up to the conference.

"What the heck is going on with the star-nosed moles? No one really knew when I started studying them in the 1990s," Catania says. The biologist, who now studies everything from electric eels to tentacled snakes, started out by studying star-nosed moles as an undergraduate working at the National Zoo.

Since then, research by Catania and others have shown that the star-nosed mole does not detect changes in electric fields with its eponymous snout. Instead, the star is a mind-blowingly sensitive touch organ. “This star is the size of your fingertip and it has five times the number of nerve fibers in the whole human hand,” Catania says.

“The star acts like an eye, except for touch,” Catania says. “It’s constantly shifting the star around—like we shift our eyes around—so it can examine one part of the touch world in high resolution.”

The mole uses this to ‘see’, and also to hunt, swiftly eating any bug unfortunate enough to get in its way. It chows down at a record-setting pace, only taking 8 milliseconds to identify its prey as a tasty morsel, and only 200 milliseconds total to eat it. That’s the fastest foraging behavior of any mammal on the planet.

In addition to being incredibly touchy, they can also smell underwater, blowing air bubbles into their waterlogged tunnels and re-inhaling them to smell their surroundings. And even though their range extends into Canada, these small mammals don’t hibernate, sticking out the winter in their shallow tunnel homes.

But don’t let it be said that these quick-eating, underwater-sniffing, wildly sensitive creatures don’t do anything for their neighbors. Catania has studied the moles in the field, and found that the star-nosed mole is also an engineer of the swampland. Using their shovel-like front paws, they dig tunnels through marshes, providing an underground superhighway for other mammals, including several different species of shrew and weasels, to enjoy.

“How all those animals are interacting is an unknown, really fascinating question, because they’re all using these same tunnels,” Catania says. “I would love to know what’s going on down there.”