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

Mosquito-borne illnesses have killed captive orcas at SeaWorld

After two SeaWorld orcas died from viruses carried by mosquitoes, scientists warn that mosquito-borne illnesses may be a bigger threat to these captive animals than previously known. Captive orcas spend a lot of time stationary, close to the surface, unlike their wild counterparts. Researchers saw mosquitoes landing on the animals' backs, heads, and dorsal fins, supping on their blood.

In recent years, orcas have begun sinking boats and other orcas are following in their footsteps

For just over five years, killer whales have been ramming (and occasionally sinking) expensive yachts, sailboats, and fishing boats in waters near European coasts. Scientists believe these incidents are the result of play rather than aggressive attacks.

Some mosquitoes are key pollinators—and eat disease-carrying mosquitoes

​​There are more than 3,500 species of mosquitoes, and only a small fraction of them bite humans. They also play vital roles in the ecosystem: One young elephant mosquito, for example, can eat dozens of smaller mosquitoes that bite humans in just one day. Sometimes mosquito-gobbling species are released by humans to control other mosquitoes.

More than 20 mosquito-borne and tick-borne diseases are found in the US

Children, older adults, and people with compromised immune systems are at particular risk of poorer health outcomes from these diseases. But dog owners and outdoor enthusiasts are among those at particular risk of contracting these illnesses, which include Lyme disease, Zika, and the condition Alpha-gal Syndrome.

Scientists found that if cats in the lab ate infected rodents they could get West Nile

But beyond the lab setting there have been no known cases of cats or dogs contracting the virus this way. Instead, those animals have been sickened when an infected mosquito bit them—just as with human infection.

How Disney World keeps out mosquitos

Disney World may have been built on a swamp, but it's nearly free from the annoyance of mosquitos. That hasn't been an easy task; Disney has worked with engineers and pest specialists on minimizing the invasive bugs through a variety of different methods. This Reader's Digest article breaks down how they've successfully kept the park free from these unwanted guests.

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

We can get food poisoning from spending time in swimming pools, lakes, rivers, and ponds

Some of the same pathogens that may sicken us in food or water may also sicken us in recreational swimming environments. Bacteria can rub off of people’s (or animal’s) bodies or contaminate the water through a diarrheal episode. Washing your hands for at least 20 seconds before eating food if you are at the beach, pool, or other similar environments and being sure not to swallow the water are ways to help keep safe.

Twin studies helped scientists understand why mosquitoes like some of us more than others

A combination of carbon dioxide output, skin chemistry, genetic factors, hormones, and clothing choice can make us particularly vulnerable to mosquito bites. Watch how mosquitoes responded to one man in the video versus his wife, a research approach typically conducted with identical and fraternal twins to test mosquito attractiveness.

What are zoonotic diseases?

Interspecies interactions are a breeding ground for disease transmission. This basic background information on zoonotic disease from the Centers for Disease Control and Prevention (CDC) chronicles the different ways humans can get sick, identifies what groups are particularly vulnerable, and offers links to other resources.

How the environmental diversity of coral reefs provides potential medical treatments for humans

As immobile animals, corals and the organisms that live on them have evolved a suite of chemical compounds to prevent disease and ward off predators they cannot outrun. These include antibiotics, antivirals, and powerful toxins that target the nervous system and are studied for applications involving pain management and neurological treatments.

California condors have been vaccinated against West Nile to protect their limited population

The condors became endangered in the 20th century primarily due to lead poisoning from consuming animals shot with lead bullet fragments inside them, so condors in captivity and in the wild are vaccinated against diseases including highly pathogenic avian flu and West Nile.

Invasive species can harm infrastructure and threaten human health

The wildfires in Hawaii in 2022 were made worse by flammable invasive grasses introduced from Africa as livestock pasture, and Zebra mussels native to the Caspian and Black Seas have spread across Europe and the US, where they can clog power plant pipes. Invasive mosquitoes can carry diseases, such as dengue and malaria.

Protecting yourself from West Nile involves avoiding getting bites and clearing standing water

The best prevention against West Nile is avoiding getting bit. That means covering your arms and legs with long, loose-fitting clothes, wearing insect repellant—on top of, not under sunscreen, and making your environment as inhospitable to mosquitoes as possible, including clearing any standing water.

Hookworm infection, though risky, may help fight certain health conditions

Early clinical trial research suggests that the parasites trigger the production of specific proteins that quiet our immune systems. This keeps the parasites from being killed, but it also quiets the inflammatory response that underpins allergies, type 2 diabetes, celiac disease, and other autoimmune conditions. Researchers still caution that infection with too many hookworms can cause serious medical complications and that this is not a standardized or approved medical treatment.

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.

Environmental conditions, shifting immunity, and viral strain could help explain 2025 spike

The surge in HFMD in the summer and early fall of 2025 in the mid-Atlantic could be the result of a confluence of factors, including a more virulent strain of disease-causing virus, good environmental conditions for the virus to spread—hot, humd—and a potential immunity gap among kids due to milder HFMD outbreaks the previous year.

Zoo animals have developed allergies, too

Although scientists do not know if allergies manifest among wild animals—and if animals can survive with them—in a zoo setting, veterinarians have observed zoo animals with common allergy symptoms, including itchiness, crusty skin, and runny eyes. Veterinarians have identified Asian elephants with pollen allergies and at least one jaguar with an allergy to fleas.

Read a study about racial differences in Lyme disease diagnosis

The research published in September 2025 examined differences in Lyme disease diagnosis among Medicaid and Medicare beneficiaries using data from 2016 to 2021. It notes that though US Lyme disease surveillance data indicates more than 90% of diagnosed Lyme cases are among white people, people of color—particularly those who identify as Black or African American—have higher rates of more severe disease of Lyme, with symptoms including arthritis and neurologic impacts.

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.

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.)

How the gut microbiome can affect heatstroke risk

Some research suggests that our gut microbiome influences our risk of exertional heatstroke. If exercise boosts our body temperatures to unsafe levels, increasing gut permeability, that can cause a "leaky" gut—allowing bacteria and other gut microbes to leak into the bloodstream and potentially trigger endotoxemia, a potentially life-threatening inflammatory response that can occur with heat exhaustion and heatstroke.

Research suggests the cleanliness of the ISS may make astronauts unhealthy

The International Space Station's sterile conditions deprive astronauts of the opportunity to strengthen their immune systems through microbial exposure. To address this problem, future missions may use probiotic-based cleaners and foster diverse microbes in space habitats.

COVID accelerated antibiotic resistance

The COVID-19 pandemic was caused by a virus, and viruses can’t be treated with antibiotics. But recent research finds that COVID patients were given a tremendous amount of antibiotics, contributing to the problem of antibiotic-resistant bacteria. Why? This NPR feature sheds light on an unexpected side effect of the pandemic.

This real-time tracking of the hantavirus cruise ship outbreak in May 2026 offers a unique glimpse into the global reach of the outbreak and whether the virus sickened passengers and their communities around the world.

Children are at increased risk of contracting swimmer's ear

Kids may be more likely to spend time at the pool so they have that water exposure. They also tend to have narrow ear canals, a prime location for water to get trapped. Frequently wearing earbuds or excessively trying to rid ears of earwax, however, can also increase the chances of painful swimmer's ear infections at any age.

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

The Southern Ocean's powerful circular current isolates organisms in its environment

The spiralling current churns up nutrients across the frigid waters, leading to the evolution of fantastical organisms, including century-old starfish and colossal squid, and unique adaptations, including the icefish's clear blood and organic antifreeze, over the past 30 million years.

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

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

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.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

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.

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

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

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.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

The animatronic shark from Steven Spielberg's 'Jaws,' the first modern blockbuster, was a complex underwater apparatus called 'Bruce.'

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.

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

Between 10 million and 50 million people in the US develop rashes from poison ivy, poison sumac, and poison oak each year.

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.

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.

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

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

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.

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.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.