Rodents and Shrews

A picture of Calhoun in a mouse utopia in 1970

This Old Experiment With Mice Led to Bleak Predictions for Humanity’s Future

From the 1950s to the 1970s, researcher John Calhoun gave rodents unlimited food and studied their behavior in overcrowded conditions

An artist's impression of the shrew-like Krusatodon kirtlingtonensis, which a new study suggests lived long and matured slowly, in contrast to modern small mammals.

Two Rare Jurassic Skulls Could Help Unlock the Secrets of Mammals' Evolutionary Success

Fossils reveal a prehistoric, mouse-like creature matured slower and lived longer than similar mammals of today

Wedge-tailed shearwaters surprised scientists by showing up after rats were eradicated on Tromelin Island—a place, in the Indian Ocean, where the seabirds hadn’t been documented breeding before.

After Rats Were Eradicated From This Small Island, Seabirds Thrived

Tromelin Island became a safe place for birds once the invasive mammals were eliminated

Toxins from the Colorado River toad have been ingested by some for their psychedelic and medicinal effects.

A Modified Psychedelic Toad Toxin Reduces Signs of Depression and Anxiety in Mice, Study Suggests

Colorado River toads produce a psychoactive toxin that some have claimed has medical benefits. The new research suggests these benefits could be achieved without hallucinations

Previous research had found leprosy in modern red squirrels, and genetic analysis suggested the strain was closely related to leprosy found in medieval humans.

Medieval Squirrels and Humans May Have Spread Leprosy Back and Forth

Archaeologists uncovered evidence of leprosy in a medieval red squirrel in England, and DNA evidence revealed the strain was similar to what was circulating in humans at the time

Cats can be infected with plague by flea bites or by eating infected rodents.

Oregon Resident Catches Rare Case of Plague, Likely From Their Cat

The patient was treated during the earlier stages of disease, so the community faces little risk, according to health officials

Captured mid-hop, the floppy feet of a white hare were indeed good luck for this photographer.

Celebrate Winter in the Wild With 15 Photos of Animals Enjoying the Snow

These chilly but cute creatures will remind you what’s so wonderful about winter

Human tears may contain an odorless chemical substance that reduces aggression, a new study finds.

Sniffing Women's Tears May Reduce Aggression in Men, Study Finds

The findings, which may extend to all humans, suggest emotional tears might serve an evolutionary purpose

After peanut butter failed to attract the giant rats, researchers turned to sesame oil.

See the First-Ever Photographs of a Rare Giant Rat That Lives Only on One Pacific Island

The elusive and critically endangered Vangunu giant rats are at least twice the size of common rats

New research suggests rats can mentally navigate to locations they've visited before.

Rats Can Use Imagination to Navigate in Virtual Reality, Study Finds

Like humans, the rodents appear to be able to visualize walking through locations they've previously visited

A leaf-eared mouse called Phyllotis vaccarum

Biologists Find 13 Freeze-Dried Mouse Mummies Atop Andean Volcanoes

These cold, arid and oxygen-poor summits are akin to conditions on Mars, prompting questions about how the rodents got there—and how they survived

The life cycle of the parasitic rat lungworm involves rats spreading it to snails and slugs, which pass it back to rats.

Parasitic, Invasive Worm Found in Rats in Georgia

While the worm can sicken people, few human infections have been reported in the U.S., and it typically doesn’t require treatment

Rats make a high-pitched sound similar to laughter when they're being tickled.

Tickling Rats Reveals a Brain Region Linked to Laughter and Play

This group of neurons could someday inform the treatment of depression and anxiety in humans, scientists say

Kathleen Corradi, New York City's new director of rodent mitigation, at a press conference on April 12, 2023.

New York City's First 'Rat Czar' Will Fight Its Rodents

Kathleen Corradi says she will "bring a science- and systems-based approach" to the job

The critically endangered ‘akē‘akē (the Hawaiian name for the band-rumped storm petrel) is one of the species that could benefit from rat-free habitat on Lehua Island, Hawai‘i.

This Tiny Hawaiian Island Is Free of Invasive Rats

Now scientists are trying to coax back lost seabird colonies

Though this particular Arctic ground squirrel died during the Ice Age, these rodents still live in the Yukon Territory and Alaska today.

This Mummified Ice Age Squirrel Was Found Frozen in Canada

Scientists identified the curled-up creature as an Arctic ground squirrel that likely died while hibernating some 30,000 years ago

The small mammal's foot in the fossil of the microraptor.

This 120-Million-Year-Old Dinosaur Fossil Had a Mammal Hiding in Its Stomach

The finding represents only the second recorded instance of a dinosaur consuming a mammal

More than 150 people die every day from synthetic opioids.

Scientists Create a Vaccine Against Fentanyl

Researchers hope the vaccine, which blocked the drug from entering rats’ brains, could help reduce overdoses in humans

The study found that the human particpants and rats jerked their heads in a similar rhythm as the songs played. 

Watch These Rats 'Dance' to the Rhythms of Mozart, Lady Gaga and Queen

Moving accurately to a song’s beat was long thought to be a skill unique to humans, but new research suggests rats can do it, too

As of June 15, the World Health Organization had recorded a total of 2,103 confirmed monkeypox cases in 42 countries. Pictured: a colorized transmission electron micrograph of monkeypox virus particles (green) cultivated and purified from cell culture

What You Need to Know About the History of Monkeypox

Mired in misconception, the poxvirus is endemic in certain African countries but was rarely reported in Europe and the U.S. until recently

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