Harvard drowned rats for this?

What rodent cars can tell us about human joy

Neuroscientist Kelly Lambert and her colleagues taught rats to drive in a mini car. She writes her findings from this unconventional experiment, sharing that positive and fun experiences can sculpt the brain just as powerfully as stressful ones. Click to learn more about how the apparent joy of these rodents seemed to enhance their neuroplasticity.

Supertoxic rat poisons are wreaking havoc on unintended targets, including predator birds, mammals, amphibians, crustaceans, and insects.

Rat taxidermy can be a tender, if unsettling, communal activity

At a rat taxidermy class in Chicago, participants use previously deceased rats, usually from lab experiments, as they learn the art of preservation step-by-step. Despite the gore, the act can engender tenderness toward the animal and prompt healthy reflection on death and dignity.

Scientists William Russell and Rex Burch proposed in 1959 that when it comes to animal testing, there should be 'three Rs'—replace animals wherever possible; reduce their numbers; refine how they're treated.

Six of history's most unethical human experiments, from deliberate flu exposure to withholding syphilis treatment

Some of the progress made in mental health treatment, vaccines, blood transfusions, and more came about before the advent of consent and ethics committees, resulting in serious physical and psychological harm that participants in studies were not even anticipating.

Pig brain cellular activity was restarted hours after death in study published in 2019

Yale University scientists restored basic cellular activity and circulatory function in pig brains about four hours after death with a synthetic cocktail of preservatives and nutrients. This work— which didn't restart electricity activity in the brain or consciousness—could help advance future human stroke and brain injury treatments.

Animal brain studies show brain activity similar to what we'd expect during dreams, but parsing whether animals are truly dreaming depends on how one defines dreaming and how scientists could prove it.

Read why one man agreed to get a pig kidney in 2025 to replace his own failing organ

The 68-year-old New Hampshire man told USA Today that a motivator for the experimental surgery was his belief that he was going to die anyway, and other people suffering from kidney disease could gain valuable insights. Yet the surgery bought him time—he lived 271 days with a pig organ and later received a human kidney transplant. Clinical trials began in 2026 to test the pig xenotransplants in more people.

This Harvard philosophy professor suggests we should rethink our relationship with animals

Christine Korsgaard, a professor of philosophy at Harvard, wrote a book arguing that humans are not more important than other animals and that we should improve our treatment of them. In her view, we have a duty to value the life of our fellow creatures not just for their utility, but for their existence as sentient and conscious beings.

Scientists have demonstrated IVF to help critically endangered rhinos

Scientists have used the technique to create embryos from eggs harvested from captive southern white rhinos and implanted into a southern white rhino. They hope to use this proof of concept to eventually use IVF to revive the population of northern white rhinos, which are extinct in the wild and have no living males left, using a precious reserve of frozen embryos and a surrogate southern white rhino mother.

A first-of-its-kind clinical trial taps livers from gene-edited pigs to clean blood

The experimental dialysis-like treatment from United Therapeutics, eGenesis, and OrganOx, is designed to help people with liver failure. The therapy, which involves attaching the modified pig liver externally, filters a patient’s blood so their own livers can temporarily rest and perhaps heal.

Early 20th-century debates about horses with 'paranormal mathematical abilities' helped shape modern approaches to psychological research.

What revisiting a 1979 experiment reveals about ecosystem recovery after deep-sea mining

A 2023 study co-led by the National Oceanography Centre and the Natural History Museum, London, found that tracks made by the mining vehicle remained largely unchanged since 1979. Small animals, such as amoeba-like xenophyophore, were seen in the cleared areas, but sightings of larger animals known to live in the region were much rarer. (Some readers may experience a paywall.)

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 economics of horseshoe crab blood

Horseshoe crabs are older than dinosaurs and have survived five mass extinctions that wiped most life from the planet. But it's only now that their future as a species is in danger. This blood, worth about $60,000 per gallon, is hyper-sensitized to certain bacteria that are fatal to humans. This 17-minute podcast dives into humanity's pursuit of horseshoe crab blood, a "somewhat magical" mixture heavily relied on by the pharmaceutical industry.

Listen to how the 1902 'poison squad' experiments changed food safety in America

As part of government research, a group of young men were paid to eat standard American food—replete with food additives like borax and formaldehyde—which revealed the dangers of unregulated food. The work was led by the first FDA commissioner, Harvey Wiley, who helped end the "century of the great stomachache."

Chinese scientists transplanted a pig lung into a human being in 2025—but it had to be removed.

Harvard and MIT researchers are developing life-saving tattoos

Tattoos aren’t just a fashion statement. Scientists are trying to find life-saving applications for them. Harvard and MIT researchers are developing tattoo inks that react to body chemicals, alerting diabetics to blood sugar fluctuations or athletes to dehydration. Someday, patients may observe their body chemistry with tattoos that change colors.

Xenotransplants are an experimental last resort for the terminally ill when they cannot or will not receive a human organ.

Pig-to-human transplant work has raised concerns about donor pigs' living conditions.

At a 2026 cancer conference, news that a novel pancreatic cancer drug doubled survival times in clinical trials led to a standing ovation.

Using mosquitoes to vaccinate bats could curb the spread of deadly diseases.

See how pig heart valves have been placed in humans since 1965.

Watch an expert's take on the rare disease hantavirus—and why it's not of great concern to the general population

This rare zoonotic disease, transmitted to humans primarily through infected rodent droppings, urine, or saliva, is rarely spread between people. The disease was of particular concern in spring 2026, when an outbreak occurred on a 150-person cruise ship, prompting a flurry of action, including contact tracing for passengers in their home countries. The disease can be fatal. But early care—primarily oxygen support—can help patients survive.

The story of the 1945 Minnesota Starvation Experiment

Amid the severe conditions of World War II, researchers were eager to learn the effects of starvation in a controlled study. This podcast dives into a yearlong study of 36 men at a Minneapolis college who endured a six-month period of semi-starvation, where their caloric intake was halved. Results from the experiment became a landmark study in human starvation.

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.

Cross-species transplantation has been attempted in medicine for more than 300 years.

Dr. Henry Heimlich, famous for his antichoking technique from the 1970s, was a proponent of controversial and discredited approaches, including infecting cancer and HIV patients with malaria to try to trigger a heightened immune response.

Scientists can suck animal DNA from the air

A look at how researchers filtered the air around two zoos and identified genetic material from dozens of species, a technique that could help track and conserve wildlife.

US federal researchers are blocked from putting certain human cells in animals

In 2015, US policymakers put a halt to any government-funded work that would insert human stem cells into animals. The reasoning was that human cells might spread through the animal's body and perhaps to its brain, blurring the line between humans and nonhumans. The ban remains in place today even as gene-edited pig parts are being placed in humans.

The scandal that rocked stem cell research

In 2014, a Japanese research group published a paper suggesting ordinary cells could be reverted to pluripotent stem cells by subjecting them to external stressors. The results generated interest but could never be replicated. The lead researcher was accused of fraud, and the group’s supervisor committed suicide.

River dolphins manhandle an unlucky anaconda

The natural world around us is endlessly inspiring, and fascinating, and often very odd too: like when researchers snapped a photo of Bolivian river dolphins swimming around with a Beni anaconda snake in their mouths, for example.

The US military, concerned about potential deployments worldwide, has long funded experimental hantavirus vaccines and therapies.

Collaborations between the military, biotech, and academic researchers led to an experimental antibody treatment for the Andes hantavirus strain—the one that more readily passes between humans. As of spring 2026, it had only been tested in animals. The US Army has also tested a potential hantavirus vaccine in people. It published early findings in 2023 that seemed promising, eliciting some immune system response. (Some users may encounter a paywall.)

Maryland required cholera researchers to fly a yellow warning flag—signifying quarantine dangers in the 1970s

University of Maryland Hospital researchers intentionally infected volunteers with the cholera bacterium in the late 1970s to further their understanding of the disease. They proceeded with this work following the recommendation of a US government panel. (Some users may encounter a paywall.)

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Meet Clever Hans, the 1900s horse that was believed to be able to solve math equations and read German

When Clever Hans was prompted with math questions, he responded by tapping his hoof to indicate his answers. Even a panel of experts found no indication of trickery in the horse's demonstrations. However, psychology student Oskar Pfungst found that Hans stopped tapping once a subtle cue on his owner's face told him to stop. The cues were so subtle that Wilhelm von Osten didn't even know he was giving them.

Eleven deaf men played a pivotal role in America's human spaceflight program

In the mid-20th century, 11 deaf men volunteered for a series of experiments that offered unprecedented insights into the effects of weightlessness on the human body. Most of the men had become deaf in early childhood as a result of spinal meningitis, a condition known to damage the vestibular system and make them less susceptible to motion sickness. For a decade, these men participated in extreme motion sickness situations, including living in a slowly spinning room, spending time in centrifuge pods designed to simulate hypergravity, and flying in parabolic flights sometimes referred to as the "Vomit Comet." (Some users may experience a paywall.)

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.

Pigs are of particular interest for xenotransplantation because they are close to human size, are easily raised in captivity, and have large litters.

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.

Can humans delay or reverse old age?

We're not sure yet. Researchers at the University of California San Francisco are studying why some conditions and behaviors, such as low-oxygen environments and exercise, benefit the aging process, hoping to reveal potential health applications. Some of this research focuses on klotho, a naturally occurring age-regulating hormone named after the Greek Fate Clotho. Animal studies on klotho brain injections found subjects had improved memory recall and age-related degeneration resistance.

Model organisms like yeast, mice, and flies help scientists decode the human body

Some species are used to quickly study the effects of human diseases and treatments because they are short-lived and have similar systems to those found in humans. Bacteria, like E. coli, have been used as human proxies given their rapid growth and ease of genetic manipulability.

Research advances suggest death takes much longer than we realized

Recent research indicates that organs, including the brain, are better at handling a lack of oxygen after the heart stops beating than previously known. Such findings may open up possibilities that include someday reversing certain death processes and expanding the availability of organs available for organ donations. (Some users may experience a paywall.)

How Seabiscuit's DNA made him a winner

Seabiscuit's sudden success in the sport has been framed as a classic against-the-odds sports story. One Binghamton University molecular physiologist wanted to go a bit deeper, though, to see how much genetics played a role in the horse's legendary career. Using the horse's silvered hooves, his research team discovered that Seabiscuit's genotype was typically associated with late bloomers, a finding confirmed by the horse's track record.

Genetic engineering mice is one idea to reduce Lyme disease transmission

Wild white-footed mice are the main carriers of Lyme. A research team is hoping to genetically engineer mice, using CRISPR, to make the animals immune to Lyme. They're proposing a field trial where they would insert a gene with an antibody to Lyme infection to break the disease transmission cycle on a private island and then try it in Nantucket if that goes well. Simply killing the mice isn't an option because it would upend food webs. Unlike traditional vaccines, this "heritable immunization" would pass from one generation of mice to the next.

No one is tracking the total number of animals used for research across US labs, though partial data without any rodents puts the 2024 count above 775,000 animals, including some 40,000 dogs and 100,000 primates.

Supplements ahead of exertional heatstroke helped protect mice against brain damage

In the lab, mice dosed with probiotics prior to inducing exertional heatstroke, had better cognitive outcomes. This evidence underscores the links between the gut microbiome and the brain, at least in rodents.

The hormone that spreads love and helps fish share fear

Scientists consider emotions like fear and empathy to be among the oldest evolutionary behaviors observed in mammals. Yet to date, how these reactions are processed in the brain, regardless of species, is not well understood. A new study reveals how the chemical oxytocin—known as the "love hormone" in humans—helps let fish know when their friends are in danger.

Some say baseball's drug problem goes back to the late 1800s

At age 32, pitcher James “Pud” Galvin was feeling tired and decided to take "the Brown-Séquard elixir," which contained a testicular fluid from dogs and guinea pigs, believed to invigorate tired bodies. It might've worked: Galvin pitched a two-hit shutout the next day.

Scientists may have discovered why gene-edited pig kidneys are rejected in humans

In November 2025, researchers studying how a brain-dead donor’s body responded to the transplantation of a genetically engineered pig kidney, published that they’ve identified immune system reactions that may explain why these pig organs get rejected. What’s more, they were able to reverse the rejections with an already available drug combination and the kidney functioned well. They also pinpointed a way to detect a potential rejection up to five days sooner.