It won’t win any beauty contests, but in terms of talent, the weird-looking star-nosed mole is the one to beat. The little mole, scientifically known as Condylura cristata, commonly lives in the wetlands and marshes of the eastern United States. As its name implies, it has a star for a nose — specifically, a snout made up of 22 fleshy tentacles, that form a fleshy, circular star. And with that star, says biologist Kenneth Catania of Vanderbilt University, the little mole can do some remarkable things.

For example, Catania, who has been studying the unusual mole since his graduate student days at the University of California at San Diego, recently discovered that star-nosed moles have the odd habit of blowing bubbles underwater through their nostrils. It’s not mere play. Using a high-speed camera, Catania filmed the moles as they created the bubbles — at a rate of between 5 and 10 bubbles per second, or about the same speed at which other rodents sniff — and found that most of the bubbles are immediately sucked back into the nose. He also discovered that the moles aim their bubbles at specific targets; they’ll blow out a bubble to touch the surface of an object, such as a piece of an earthworm (a star-nosed mole delicacy) or a small fish. “When these bubbles come into contact with an object, it is almost inevitable that odorant molecules” — those that impart smell — “will mix with the air and be drawn into the nose when the bubble is inhaled,” Catania says. That means, he says, that the mole uses the bubbles to smell. The finding came as a big surprise to Catania and other scientists, because mammals weren’t thought to be able to smell underwater at all, much less smell by blowing bubbles.

A star-nosed mole’s snout is made up of 22 tentacles

In previous work, Catania found that the mole’s tentacled snout enables it to perform another prodigious feat: it can detect and gulp down prey with astonishing speeds. The moles, which are nearly blind, use their tentacles to survey their murky marshland habit. The fleshy tentacles, each of which is covered with over 25,000 sensory receptors (called Eimer’s organs), are used to repeatedly touch objects near the mole. Catania found that when a mole finds something that could be food, it needs just 250 milliseconds (a quarter of a second) to identify it, decide if it is edible, and eat it. Of that time, Catania found, only 8 milliseconds — 8 thousandths of a second — are actually used for the mole’s brain to make the identification. In fact, the mole makes these decisions so fast that it often messes up. It may pass by food that’s edible, then quickly head back to give it another feel. That inefficiency, Catania says, shows that the mole is “operating at, or near, the limit set by the speed which the mole’s nervous system can process touch information.” In other words, it’s literally impossible for the mole to forage any faster than it does.

Holly is one of the best and brightest detectives on the Massachusetts State Police Force. She is an expert in her ability to assemble clues while tracking missing persons or hunting down criminals. How did she get to be so good at her job? That’s easy — she works like a dog.

As we learn in NATURE’s Underdogs, Holly is a bloodhound once slated for the death chamber. In her youth, she was so destructive that no family could manage her as a pet. Passed from home to home six times before her first birthday, she had little prospect of making it to adolescence. But then, someone entered her life who sensed that behind Holly’s troubled eyes was an animal with phenomenal natural abilities.

For the past 25 years, Larry Allen, a member of Barbour County Tactical Search and Recovery Teams in West Virginia, has been training bloodhounds for law enforcement agencies across the country. Rescuing problem dogs like Holly, he works them through their behavioral issues so that they may achieve their full potential as “gainfully employed” trackers. But Allen insists that training is a relatively small part of what makes these dogs so good at what they do. “The working ability of a bloodhound is 75 percent nature and 25 percent nurture,” he says. And the nature part of the equation resides in the animal’s exquisitely designed nose.

Holly now serves as an olfactory sleuth with the K-9 corps of the Massachusetts State Police.

Often called a nose with a dog attached, the bloodhound is so adept at scent tracking its trailing results is admissible evidence in a court of law. Its outstanding ability to read terrain with its nose is primarily due to a large, ultrasensitive set of scent membranes that allows the dog to distinguish smells at least a thousand times better than humans.

Researchers have estimated that a bloodhound’s nose consists of approximately 230 million olfactory cells, or “scent receptors” — 40 times the number in humans. Whereas our olfactory center is about the size of a postage stamp, a dog’s can be as large as a handkerchief — according to Allen, it is among the largest in canines. “The physical size of their olfactory area far exceeds most other working scent dogs,” he says. “The larger capacity combined with the desire to work makes them a very good tool.”

When a bloodhound sniffs a scent article (a piece of clothing or item touched only by the subject), air rushes through its nasal cavity and chemical vapors — or odors — lodge in the mucus and bombard the dog’s scent receptors. Chemical signals are then sent to the olfactory bulb, the part of the brain that analyzes smells, and an “odor image” is created. For the dog, this image is far more detailed than a photograph is for a human. Using the odor image as a reference, the bloodhound is able to locate a subject’s trail, which is made up of a chemical cocktail of scents including breath, sweat vapor, and skin rafts. Once the bloodhound identifies the trail, it will not divert its attention despite being assailed by a multitude of other odors. Only when the dog finds the source of the scent or reaches the end of the trail will it relent. So potent is the drive to track, bloodhounds have been known to stick to a trail for more than 130 miles.

A bloodhound’s outward appearance also adds to its tracking ability. Loose, wrinkled skin around the face helps trap scent particles and long, drooping ears that drag on the ground collect odors and sweep them into the nostril area. The dog’s long neck and muscular shoulders, which slope into its strong back, allow it to track close to the ground for miles on end.

For the past two centuries, these natural-born detectives have proven legendary in their role in law enforcement. One of the greatest sleuths in canine history was a Kentucky bloodhound called Nick Carter. His dogged persistence led to the capture and conviction of more than 600 criminals throughout his illustrious career.

Despite the technological advances of our current age, many experts agree that these canines are a greater asset to a police force than some of the best high-tech surveillance equipment. Their extraordinary ability to discern a cold trail has sent them on fruitful missions, following tracks over 300 hours old.

But there’s more to becoming a good police dog than simply an acute sense of smell. The dog must also have a predisposition to working with a handler, be eager to please, and have a strong play drive. “The bloodhound’s whole biological makeup enables it to track like no other dog. Such skills are gifts of nature,” says Aidan Woodward, the associate producer of Underdogs. “However, without the disciplined and focused assistance of the dedicated trainer, a novice bloodhound may not reach anywhere near the potential it could.”

Allen was able to provide the gentle discipline that Holly needed, though he initially had his doubts. “The first time I saw Holly, all I could think was, how am I going to make this puppy into a working dog in 12 weeks?” he recounts. “Little did I know that she would develop a love for the game within two weeks and go on to be one of the best trainees I have ever had. The more that I worked with her, the more solid she became and the more she became my partner.”

After 12 short weeks of training, Holly had polished her natural skills as a tracking dog and was ready to begin her new career with the Massachusetts State Police. “Parting with Holly was very difficult,” Allen admits. “Compare it to having your child get married and move to the other side of the world the next day.”

But he is thoroughly proud of all she’s accomplished. “The best part of working as a trainer with the dogs from rescue is watching them develop skills and confidence in themselves,” offers Allen. “The ultimate reward is having a dog that you trained be involved in saving a person’s life or tracking down a violent criminal.”

As for Holly, she has been given a second chance and a fresh new start in life. What could be more rewarding than that?

Star-Nosed Mole (Condylura cristata)

• Type: Mammal
• Family: Talpidae
• Habitat: Areas with moist soil and poor drainage, such as forests, marshes, peat land, and the banks of streams and ponds.
• Location: Native to eastern North America, from Quebec and Newfoundland, south to at least Virginia, and west to North Dakota. Also found throughout the Appalachian Mountains.
• Diet: Carnivore (vermivore)
• Average lifespan in the wild: 3-4 years
• Size: Length: 6-8 inches (15-20 cm); tail: 2.6-3.4 inches (65-85 mm)
• Weight: .12 lbs (55 g)

Set aside the 22 fleshy pink tentacles that form the “star” on the nose of this mole, and it remains an odd-looking creature. The mole, which is covered in dense, blackish brown, water-repellent fur (ideal for its life in moist, mucky soil), has broad, scaly feet with large claws for fast digging, a stout cylindrical body, and a long thick tail that swells with fat to three to four times its normal size during the winter. The males’ testes also expand during the mating season (once yearly, roughly mid-March to April, although females may breed a second time if their first litter is unsuccessful), and can reach nearly nine percent of the animal’s entire body weight.

Appropriate to its life largely underground, the star-nosed mole is essentially blind. However, thanks to the tentacled star, the mole has perhaps the best sense of touch of any mammal in the world.

Each of the .03-.16 inch-long (1-4 mm) tentacles is covered by about 25,000 minute touch receptors, known as Eimer’s organs. The receptors come in three varieties, including one that senses the microscopic texture of objects, believed to be unique to the mole. The tentacles, which are also thought able to detect the minute electrical fields produced by aquatic animals as they move through water, move with lightning speed, and can touch as many as 12 objects per second. This allows the mole to rapidly identify and consume small prey, which consist of worms (including leeches), aquatic insects like dragonflies and damselflies, and the occasional terrestrial insect, mollusk, and small fish.

Star-nosed moles are currently relatively common, but the destruction of wetlands could adversely affect their status.

Did you know? The star-nosed mole blows and re-inhales air bubbles underwater as fast as five to ten times per second to track prey.