The hormone that spreads love and helps fish share fear

Fear (and stress) can be contagious via pheromones secreted by the body

While seeing someone else in a panicked state may induce a stress response, researchers have found stress can be literally contagious—chemicals contained in sweat and other secretions can trigger stress hormone release in others. Theories suggest this feature is an evolutionary adaptation to protect groups from danger.

Humans are wired to pick up on each other's emotion, making laughter contagious

The reaction plays a key role in establishing interpersonal connections and relieving stress by releasing endorphins—feel-good hormones. A 2021 study identified at least 65 animal species that produce playful sounds, such as laughter.

Love and heartbreak trigger powerful, neurochemical-driven changes in the body

The feeling of falling in love floods the brain with dopamine, oxytocin and serotonin, which collectively dull pain and boost immunity. However, the loss of these chemicals during a break-up produces withdrawal-like symptoms and heart issues, such as high blood pressure.

Deep sea fish rely on a molecular strengthener to prevent being crushed

Trimethylamine N-oxide (TMAO) stabilizes hydrogen bonds and prevents water and proteins within organisms from being misshapen under immense pressure. Compounds called piezolytes protect cellular membranes from being crushed in regions like the Mariana Trench, where pressures are 1,100 times greater than surface atmospheric pressure.

How the heart achieves its first beat

Scientists observed zebrafish embryos as they grew and isolated the several-second-long initial heartbeats to better understand this crucial moment in every heart's life. The zebrafish's heart starts beating 20 hours into their existence. Each heart cell activates electrically at random, without rhythm. As these cells mature, they become more sensitive to electrical charges; as they all fire, a rhythm is established and a pulse is born.

A 'fishy' scent does lead to mistrust

In experiments where people were exposed to a literal fishy smell they were less willing to cooperate with others in economic games requiring trust, but that wasn't the case when they were exposed to another bad odor—the smell of flatulence.

How can octopuses and MDMA help scientists understand the human brain?

Research shows that psychedelics may induce something called "critical periods" in the adult brain, which can make our brains more open to learning and changing, like they once were back in early childhood. Psychedelics similarly change how social creatures like octopuses behave, which demonstrates that these animals could help us better understand our own neurobiology.

The limbic system drives emotion, memory, and survival instincts in the brain.

This interconnected group of brain structures—including the amygdala, hippocampus, thalamus, and hypothalamus—processes emotional responses, regulates bodily functions, and plays a key role in memory and learning.

There’s a psychological explanation for ‘FOMO,’ or the fear of missing out

This video breaks down FOMO—what it is, how it works, and why it happens—showing how social comparison and uncertainty trigger anxiety that pushes people toward risk-taking and constant checking behaviors.

Synthetic pheromones may protect coral reefs by attracting their predators

Researchers in Australia and Japan have developed these nontoxic chemicals to attract crown-of-thorns starfish, which consume corals that make up the Great Barrier Reef. As of 2026, synthetic pheromones have been shown to be effective in lab trials, and future field trials will attempt to lure starfish into areas for mass removal.

Swimming in schools helps some fish conserve energy in turbulent flows

Scientists studying groups of giant danios swimming in turbulent waters found that the fish used up to 79% less energy than they did when swimming individually in the same conditions. The same fish were found to use the same amount of energy in turbulent and calm water when in schools.

The fish can climb walls

Scientists in Brazil captured rare footage of bumblebee catfish climbing waterfalls. How they do it is clear, but why remains a mystery.

A primer on human tears

Tears are one of the many behaviors that differentiate humans from the rest of the animal kingdom. Why do we cry? This comprehensive and well-written essay explores various theories about why we cry, observes tear fluid as the only one that does not elicit disgust, and attempts to interpret the meaning of tears in different circumstances. See what all the fuss is about here.

Charles Darwin studied goose bumps by scaring zoo animals in London with a stuffed snake

Read the famous naturalist’s work from the late 1800s, detailing how he sought to draw comparisons between how animals and humans respond to fear. As part of that work, he exposed monkeys and a peccary to a stuffed snake and noted the animals’ hair-raising fear response.

What we can learn from how penguins express affection

Pebbling, a term used to describe small acts of love within a relationship, comes from penguins. Male gentoo penguins, a species of penguin that lives on sub-Antarctic islands, present pebbles to their potential mates later used to build nests. This small but helpful act is something we humans can learn from. Think of the “pebbles” you can share with loved ones on a daily basis.

Read the 2012 study about captive orcas and the threat of mosquito-borne illness

Written by orca trainers who went on to become scientists, it states mosquitoes bite orcas at night when the animals hang out close to the surface. What's more, antibiotics used to keep captive orcas healthy also may depress their immune response, boosting the risks of them being unable to fight off diseases like West Nile Virus and encephalitis, which have killed orcas at US water parks.

Listen to recordings of different fish species

Scientists have captured and curated this collection of species-specific recordings, helping us gain a deeper understanding of underwater ecosystems. Uncover their sounds, which include a lot of thumps, burps, and grunts.

Dolphins have doulas too?

For the first time in over a decade, a dolphin gave birth at Brookfield Zoo, and she didn’t do it alone. Right beside her was another dolphin, acting as a doula. Why do dolphins support each other this way? The answer reveals something incredible about how animals care for one another.

Neural replays in mice help explain food aversions

Princeton University scientists published research in 2025 analyzing how mice learn to associate certain foods or flavors with feeling ill—even when there’s a time gap between eating something and feeling sick. The work, performed with grape Kool-Aid and injections of a substance that made mice sick, traced the literal “gut reaction” of how gut distress signals are linked to neural replays of what the mouse ate.

Yawning helps regulate heat in and around the skull

All vertebrates, including solitary animals, exhibit yawning behavior, and, despite long-standing beliefs, studies show no correlation between yawning and oxygen levels. Contagious yawning may enhance group coordination and vigilance in animals and involves advanced social cognitive mechanisms.

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.

Scientists have not yet answered what the evolutionary benefit may be of menopause

Few animals are known to experience menopause, raising questions about why it would be evolutionarily advantageous to have women survive past their reproductive years. One leading hypothesis is the grandmother hypothesis—older women and other species known to experience menopause, like whales, can aid families and pass down knowledge to future generations.

Fireflies light up to provide mating signals and warnings to predators

Variations in the illumination patterns and flight paths while emitting light have been observed across firefly species. Some species instead rely on pheromones if they are primarily active during the day or have lost the ability to illuminate.

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

Harvard drowned rats for this?

Harvard's 1950s rat study was ethically questionable, but scientifically profound. One rescue attempt made rats swim 40x longer. The finding: hope isn't poetic, it's biological.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Can animals understand fairness?

Academics have long wondered if fairness is solely a concern of humans. In the largest meta-analysis to date, UC Berkeley researchers tested whether monkeys felt jealousy after receiving unequal rewards. The patterns showed low evidence for inequity aversion and instead frustration due to their expectations not being met by humans. These findings suggest that pursuing fairness and equality is uniquely human.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

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

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.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

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.

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

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.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

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.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Georgia O'Keeffe's flower paintings are often assumed to be sexual, though the artist claimed she was simply interested in highlighting the beauty of flowers that most people neglect

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.