Do trees feel pain?

Plants use physical and chemical defenses to protect themselves

Tree bark is difficult to chew and resistant to pathogens, while the waxy cuticle on the surface of leaves deters insects and microbes. Some plants possess thorns, spines, and prickles to discourage predators. Plant cells can also produce antimicrobial toxins or release compounds to alert parasitic wasps to lay eggs in attacking insects.

Programmed cell death drives leaves to fall from trees

All living things have innate mechanisms to prompt organized cell death, typically to protect the integrity of the living organism. Leaves fall from trees to allow the tree to preserve resources and bloom again in the future.

How trees transport water from roots to leaves

Trees move water to their extremities via a deft system starting from the roots to the leaves. See how it works in this short video breaking down the process in a Douglas fir.

Tree rings can reveal centuries of environmental change and natural events

The width and shape of tree rings reflect yearly growth conditions like rainfall or snowfall. Scars in the rings can record disruptions such as fires, avalanches, or earthquakes, explaining when and how those events occurred.

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

The complexity of classifying a tree

It may seem obvious to us when we see a tree, but very specific characteristics cause scientists to distinguish trees from other types of plants. This video provides a visual and verbal explanation of distinctions that separate trees from other plants like shrubs or herbs. See a scientific breakdown of these traits.

The brain doesn't seem to massively rewire following amputation—upending earlier beliefs about phantom pain

The findings, published in 2025, traced three amputees' brain-body maps and how they respond to body part movements—both before and after scheduled arm amputations. The unexpected neural stability suggests that the unchanged pathways for the missing limbs may explain why people continue to feel them so acutely.

Listen to forests around the world

Looking for something soothing to listen to? Tree.fm shares audio recordings of forests sent from people all over the world. Escape into the sounds of birds chirping, water flowing, or wind in the trees. This site offers a tool for those in need of meditative noises, and a bit of digital fresh air.

Biosphere 2 revealed limitations in maintaining wildlife in unfamiliar environments

Trees appeared to become weak and more prone to breaking because a lack of wind caused them to no longer need to develop stress wood. The extinction of pollinators—potentially due to an explosion in the population of longhorn crazy ants—was also unexpected.

Lightning may kill as many as 320 million trees each year

Ignoring the effects of tree loss resulting from lightning-induced wildfires, researchers at the Technical University of Munich developed a quantitative model to estimate the loss of these organisms due to cloud-to-ground strikes, based on global lightning data and forest structure. They expect the estimate to rise due to increased strikes resulting from climate change.

How the five senses share information with each other

The human body depends on information from the five sensory organs—the eyes, ears, nose, tongue, and skin—to react to the world around it. Each of these organs, in its own way, relies on complex circuitry to send signals back to the central nervous system.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Itching is caused by stimulated nerve cells in the skin

Scratching produces low-level pain signals to the brain, distracting from the itch. Scratching also releases serotonin, a neurotransmitter that creates a happy sensation, which resets the itch signal. This can cause a cyclical itch-scratch cycle.

How neurons give rise to thoughts

Neurons in the brain are singular nerve cells that flicker on and off or connect to each other based on incoming stimuli. The more neurons communicate by firing electrical impulses through tendrils known as synapses, the stronger their connection becomes. The electrical energy zipping along these interneural connections in an attempt to classify and respond to incoming stimuli may be what gives rise to thoughts.

There are over 20,000 trees on the National Mall

Nearly 4,000 of the Mall's trees are cherry trees, all maintained by a small National Park Service arborist team that provides year-round, science-based care to address soil compaction, root damage, and heavy visitor traffic.

Watch how your nervous system's efforts to process silence can contribute to tinnitus

Cochlear cells can be damaged in numerous ways, including aging or exposure to loud noise. If enough cells die, the auditory system can become less sensitive, prompting the brain to compensate by amplifying sound, which is likely to contribute to tinnitus.

Tornadoes produce inaudible signals to humans hours before forming

Researchers at the National Oceanic and Atmospheric Administration have found that tornado-producing storms generate specific sounds below the range of human hearing, much like the infrasonic signals produced by earthquakes and avalanches. Although difficult to distinguish from wind noise, scientists hope to build systems that use these signals to improve tornado forecasting.

The ginkgo tree is a living fossil that has not changed in over 200 million years

Having outlived the dinosaurs, the tree has no living relatives as the only surviving species of the genus Ginkgo. Its growth in undisturbed environments, pollution resistance, and foul-smelling seeds may have contributed to its survivability.

Poison ivy is in the same family as mangoes, cashews, and pistachios—and they all produce oily urushiol in their raw, unprocessed state—but they are typically prepared in ways to avoid causing human discomfort.

Deer don't get infected with Lyme disease—but ticks do feed on them

Adult ticks feed on white-tailed deer and also lay eggs on the animals, but the deer don't get sick with Lyme disease. Research published in 2023 offered new insights into why deer don't get sick from Lyme disease: It appears that the quadruped may have specific not-yet-identified immune system proteins in their blood serum that kill the bacterium.

Watch wild elephants 'mourn' their dead

Wild elephants in Samburu National Reserve in northern Kenya visited their dead matriarch's body weeks after her death and displayed behaviors that researchers are hesitant to call "mourning" though they do believe the animals are displaying a specific reaction in response to the death. The video shows elephants using their trunks to touch and explore the carcass while standing in place for extended periods, which is uncommon for the animals.

Brain studies suggest some animals do dream (sort of)

Studies on sleeping cats, rats, fish, and finches show that their brains fire as if performing actions from waking life. Spiders and insects also have REM-like sleep. Whether these findings indicate that animals dream depends on one's definition of dreaming.

Nerve axons become damaged by leprosy, so patients may lose feeling in their skin

Infection of the peripheral nerves—nerves outside the brain and spinal cord—is a known complication of leprosy. That damage can cause patients to lose their sense of touch and the ability to feel pain or temperature in affected areas, leading to accidental injury.

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.

Dead birds are often the warning sign health officials look for as a sign of West Nile danger

Public health officials look for various clues to stay ahead of outbreaks of potentially fatal diseases, like West Nile. Issues like standing, untreated pool water—detectable if the pool is turning green—or dead birds—are important to report to local public health officials.

Why don't giraffes get hypertension?

The average blood pressure of a giraffe is about double that of a human, yet they don't suffer from the symptoms of high blood pressure that humans do: stiffening of the left heart ventricle, shortness of breath, fatigue, or swollen legs and ankles. This article explains how giraffes have evolved to have the "biological equivalent of support stockings."

See how artificial Christmas trees are made

Modern artificial Christmas trees are built from bent steel frames and PVC plastic. The plastic is cut into strips and shredded to mimic the needles of an evergreen tree. See the factory process of these mass-produced holiday mainstays.

Fearology, or the study of fear, explores the difference between stress and fear

Our brains involuntarily respond to our environment and signal alarm when that isn’t always needed, triggering responses that include goose bumps. But understanding fear and how to talk our brains into calming down can improve daily life.

What is the most painful thing in the world?

Pain is famously difficult to quantify, and though our response to it may be subjective, most pain does have underlying objective causes. So what's the most painful thing of all? Many say childbirth, or a broken femur, but this article lays out one case for why, of all things, kidney stones may be the most painful experience. Prepare yourself to find out here.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

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

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

During the French Revolution, a botanist's letter asking about "dear Rhus" (poison ivy) was intercepted, leading authorities to suspect he was conspiring with the Russians.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

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

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

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.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

11 people died from firework injuries in the US in 2024.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

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

A researcher recently discovered an interview from 1967 between groundbreaking journalist Joan Didion and the Grateful Dead, years before the band became an institution.

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