Dogs smell a lot of stuff we can't, including bed bugs and chemicals in electronic devices

Efforts to create disease-sniffing capabilities for phones still can't match dogs

In this video, a scientist explains why dogs remain leaders in olfactory capabilities, outpacing technology. Scientists have attempted to create artificial "e-noses" for phones to detect early signs of disease, but so far they have not been successful.

Canine inspectors can help detect potential carriers of invasive insects

At ports of entry in the US, Customs and Border Protection agents use dogs to sniff for forbidden foods and other items that are known to harbor invasive pests. Agents also physically inspect items such as flowers to prevent entry by species that may harm US agriculture.

Two dogs were able to detect prostate cancer in 98% of patients in one study

In this small study published in 2015, two highly trained German Shepherd dogs sniffed hundreds of urine samples and were able to accurately detect prostate cancer—sniffing out certain volatile organic compounds—in almost every single case. One dog was correct 98% of the time and the other correctly identified patients 100% of the time. (Some users may encounter a paywall.)

A super-sniffer smelled her husband's Parkinson's disease years ahead of symptoms

She discovered she could smell diseases, including Parkinson's, tuberculosis, Alzheimer's, cancer, and diabetes. Working with an analytic chemist, she's learned she can smell subtle changes in odor—ones that smell consistent across individuals with the same disorder—even before symptoms manifest.

A dog's central sniffing organ is many times bigger than a human's

The olfactory epithelium, located high up within the human nose, is home to millions of olfactory neurons. A dog's olfactory epithelium is much larger—and has more neurons—than a human's, which helps to explain the animal's superior sniffing ability.

Scientists determine the smells of objects in outer space

Using spectrographic techniques, scientists determine the chemical composition of planetary atmospheres, comets, and other objects in space. Combining these chemicals in labs on Earth has revealed locations in space that smell like nail polish remover, rotten fish, and urine.

Humans can track smells on the ground quite well—our ability to crawl is a limiting factor

As part of a scientific bet, neurobiology researchers dragged a chocolate bar across the grass and sought to see if a human could track it—she could. This led to a more in-depth experiment on human olfactory capabilities and behavior when other senses were blocked.

Squeaky toys mimic prey sounds, appealing to dogs' hunting instincts

Squeaky toys provide instant feedback and gratification, and they can also prevent boredom and improve canine dental health. Some toys contain seemingly silent squeakers that use ultrasonic technology to emit sounds only audible to dogs.

Fear has a specific 'smell'—at least to machines

This excerpt from a Mythbusters episode takes on the smell-of-fear question, comparing the sweat composition of individuals exposed to snakes, rats, and scorpions with that of people exercising. Molecularly, the sweats are different to a gas chromatography machine, but to most noses would be indistinguishable.

Odor blockers use nonpolar oils to trap smelly polar molecules

In the case of feces, gut bacteria produce compounds such as skatole and hydrogen sulfide, which the brain registers as unpleasant. Because oils do not dissolve in water, they can be used to create a layer on the surface that prevents smelly compounds underwater from escaping into the air.

Scientists still don't know why DEET is such an effective bug repellent

This chemical, used to keep ticks, fleas, mosquitoes, and other nuisance bugs away, is used by an estimated one-third of the US population and has been available to consumers since 1957. Researchers theorize that multiple mechanisms may be at work to deter bugs, including perhaps masking or confusing bugs' olfactory receptors.

Cadaver dogs are helping archaeologists uncover decaying history

Archaeologists are increasingly relying on dogs to help find decaying bodies at burial sites, some of them up to thousands of years old. This is helping archaeologists to detect past remains without ever touching a shovel, which means there's less...

Bug-bitten and bedeviled: a delightful dive into the bedbug

Bedbugs can live up to 6 months without food—meaning they can lurk in your bedroom while you try to eradicate them and give you a sense that you've effectively annihilated them. What else do we know about these pesky little pests? This deep, deep...

Explore some of the trademarked scents in the US

Scents, when they are truly unique and identifiable to a particular brand, can be trademarked. Any trademark on a scent must pass two tests: distinctiveness and non-functionality. In order to be trademarked, the scent of a product can't be the primary purpose of that product (like a candle or a perfume), and the scent has to be distinct. Some of the trademarked scents include Play-Doh and the pain-relief patch Salonpas.

Environmental DNA monitoring can help detect the presence of invasive species

Genetic material that organisms deposit into water, soil, or air can be identified by analyzing samples from each environment, allowing land managers to more reliably detect and track organisms than visual surveys alone. eDNA has been used to develop early warning surveillance systems for various invasive marine species.

The genetic diversity of dogs is greater within Chernobyl than in surrounding areas

A 2023 study identified that packs of dogs located just 16 kilometers (10 miles) apart within the exclusion zone were more genetically different from one another than from stray dogs hundreds of kilometers away. Rather than radiation, this is likely the result of inbreeding within isolated packs.

Extreme heat is neurologically impairing animals

Dog bites increase in summer, birds struggle to learn, and goats pick more fights. Scientists are unraveling new details about how heat impairs animals' neurological systems.

Bacteria use chemical signals to communicate and coordinate with one another

Through a system called quorum sensing, bacteria produce and absorb compounds from their environment to identify allies or competitors and adjust their behavior accordingly. Some bacteria produce food-digesting enzymes only in the presence of similar bacteria, thereby preventing competitors from consuming their meal.

Volatile chemical contamination can last in burn areas long after urban wildfires

Lead, arsenic, asbestos, and other chemicals have been found trapped in smoke-exposed rugs, couches, pillows, and other furniture that appeared otherwise undamaged from the 2025 LA wildfires. The gradual release of these substances has produced dangerous indoor air concentrations and contributed to increased emergency room visits and abnormal blood tests.

Pets can experience vertigo, particularly older dogs

This type of dizziness is often caused by disorders of the vestibular system, and in dogs is often referred to as "old dog vestibular disease" because it tends to occur in older animals. The condition tends to resolve on its own in days or weeks. Vertigo is less common among cats than dogs, and in felines is typically caused by inner ear infections or other causes including a tumor.

How slugs helped soldiers during WWI

Slimy, squishy, slow-moving, and heroic? Slugs are land-dwelling mollusks known mostly for causing havoc in our gardens. But during World War I, slugs saved numerous soldier's lives as poison gas detectors. Learn how the unpleasant creatures earned their stripes in the battle to protect soldiers from chlorine, phosgene, and mustard gas as organic detectors.

Metal detectors identify induced magnetic fields in conductive objects

A changing magnetic field in a transmitter coil causes an electric current to be produced in materials that conduct electricity. This current generates its own magnetic field, which can be detected by a receiver coil and transmitted to a control box, which identifies the presence and depth of an object.

DNA damage and chemical stress causes cellular aging

While outward signs of aging, like gray hair and wrinkles, are easy to spot, aging changes at the cellular level are less obvious. The decline within cells stems from numerous sources, including DNA damage, oxidative stress, and accumulated waste.

'Gram-negative' bacteria: Bugs with extra defenses along their cell walls

The term 'Gram-negative' bacteria refers to bugs which react a certain way under a Gram stain test. These bacteria are harder to kill due to their double-layer cell walls with a thin peptidoglycan layer in between. This structure makes the delivery of drugs into the bacterial cell substantially more difficult.

DNA may serve as a flame retardant by self-extinguishing some burning materials

When DNA burns, phosphate groups release phosphoric acid, and nitrogenous bases release ammonia. These molecules, along with the sugar in DNA's backbone, shift the combustion reaction toward the formation of intumescent char. This puffy, carbon-rich layer protects open flames from burning the material beneath.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

'Silent' fireworks have gained more interest in recent years as a quieter celebratory option.

Tattoos remain visible on your skin thanks to immune cells called macrophages

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Poison ivy can cause rashes year-round since all parts of the plant contain urushiol, the oil that triggers our allergic response.

The Ramones' 'Pet Sematary,' the theme song for the Stephen King novel of the same name, was written while the band was admiring the writer's collection of horror memorabilia.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.