The star-nosed mole can find and swallow prey in a quarter of a second

The star-nosed mole is easy to mistake for something out of a nightmare. Sprouting from the tip of its snout is a ring of twenty-two fleshy pink tentacles, arranged like the spokes of a wheel, that twitch and probe constantly as the animal moves. That bizarre appendage is not for smelling or grabbing in the way it looks. It is a touch organ of extraordinary sensitivity, and it allows this small, nearly blind mammal to hunt with a speed that outpaces almost anything else on Earth.

Living in the wet soils and marshy ground of eastern North America, the star-nosed mole spends much of its life underground and underwater, searching for the tiny worms and insect larvae that make up its diet. In that dark, cramped world, eyesight is nearly useless. What the animal has instead is a nose that can feel its surroundings in astonishing detail.

The fastest forager ever measured

The mole’s hunting speed is not a casual estimate; it has been measured frame by frame with high-speed cameras. In research published in the journal Nature, the neuroscientist Kenneth Catania of Vanderbilt University and a colleague filmed star-nosed moles finding and eating prey, and found that the animal’s average handling time, from first touching a food item to swallowing it and moving on, was around 230 milliseconds. The very fastest captures happened in as little as 120 milliseconds, faster than a human can react to a traffic light turning green. A quarter of a second is a comfortable, typical figure for the whole sequence.

Even more remarkable is how quickly the mole decides whether something is worth eating at all. According to that work, catalogued by Nature, the animal can judge whether an object it has touched is edible in as little as eight milliseconds. That is close to the physical limit of how fast a nervous system can process information, which is why researchers describe the star-nosed mole as foraging at the very edge of what biology allows.

How the star actually works

The star is covered in more than twenty-five thousand microscopic sensory receptors called Eimer’s organs, packed onto the surface of the twenty-two rays. As the mole explores, it presses the star against the soil in a rapid series of touches, moving it so fast that the appendage seems to blur. Each touch sends a flood of information to the brain about the texture and shape of whatever the star has brushed against.

Not all of the rays are equal. One small pair near the bottom center of the star, sometimes compared to the fovea at the center of the human eye, is especially rich in nerve endings. When the mole’s outer rays brush against something promising, it swings the star so that this high-resolution central pair lands on the object for a closer inspection, a behavior detailed by the Smithsonian. In effect the mole is using touch the way most animals use vision, aiming a sharp central sense at whatever it wants to examine.

A brain wired for touch

The animal’s remarkable abilities are reflected inside its skull. A disproportionately large share of the star-nosed mole’s brain is devoted to processing signals from the star, and the arrangement of that brain tissue maps directly onto the physical layout of the twenty-two rays. The oversized central pair of rays claims an outsized chunk of that neural real estate, mirroring its importance in the hunt.

This is a vivid example of how evolution invests brain power where an animal needs it most. Just as species that rely on vision devote large regions of the brain to processing images, the star-nosed mole has built its nervous system around touch, turning its strange nose into the primary way it understands the world.

An underwater edge as well

The star-nosed mole is also one of the few mammals known to smell underwater. Researchers have observed the animal exhaling tiny air bubbles onto objects beneath the surface and then re-inhaling them, apparently sampling odor molecules the bubbles pick up. Combined with the touch-sensitive star, this gives the mole a way to detect prey even when it is diving through submerged mud and debris.

All of these adaptations serve the same relentless goal: finding enough tiny prey, fast enough, to fuel a small mammal with a fast metabolism. The star lets the mole test dozens of potential food items in seconds, discard the worthless ones almost instantly, and swallow the good ones before they can escape. What looks like a grotesque ornament on the animal’s face turns out to be one of the most refined sensory instruments in nature, and the reason a nearly blind burrower can out-hunt creatures with far sharper eyes.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.