Female Anopheles mosquito bites are the primary way malaria spreads

See this graphic of the complex malaria transmission lifecycle

Female Anopheles mosquitoes contract malaria by feeding on the blood of a human already infected with the disease-causing parasite. The parasite then develops in the mosquito's gut for one to two weeks before it migrates to the mosquito's salivary glands. Next, when the mosquito bites another person the parasite is delivered into the bloodstream of another human. This graphic further details what happens inside the human body during infection.

Anopheles mosquitoes are developing resistance to insecticides

The malaria-transmitting mosquito species is developing resistance to the insecticides used in insecticide-treated bed nets and in indoor spraying in people's homes and communities. Malaria parasites are also developing resistance to antimalarial drugs.

Pregnancy makes someone more attractive to the mosquito species that transmits malaria

Research suggests that hormonal levels can affect mosquito attraction. Pregnancy, in particular, is associated with significantly increased interest from Anopheles mosquitoes, which boosts pregnant women's malaria risk.

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.

Mosquitoes drink a maximum of 0.01 milliliters of blood in a single meal

That's roughly equal to a human drinking the contents of an entire bathtub. Females, which are the only ones that drink blood, have a sensory nerve that signals when they're getting full, but if it's disabled, a mosquito would keep drinking until it bursts—a scientist conducted that experiment.

Mosquitoes even have olfactory receptors on their sperm

Male mosquitoes, which don't bite humans, have fewer olfactory receptors than females on their antennae—they don't need them to locate blood meals. But they do have this same type of receptor located in the tail of their sperm, thought to help bring egg and sperm together.

Genetic analysis suggests Anopheles mosquitoes fed on humans some 1.8 million years ago

The 2026 paper, based on 11 species of Anopheles mosquitoes found in Southeast Asia, suggests that mosquitoes in the region likely developed their human blood preference between 2.9 million and 1.6 million years ago, overlapping with when scientists believe Homo erectus arrived there. (Some users may encounter a paywall.)

The most severe form of malaria is caused by the Plasmodium falciparum parasite

Multiple species of a single-celled organism called a protozoa cause malaria infection when transmitted by a mosquito bite. But Plasmodium falciparum is the most widespread in Africa, and the most deadly.

Wolbachia is also being used to slash mosquito numbers

The naturally occurring bacterium does not naturally infect Aedes aegypti mosquitoes, but communities in locations including California and Texas have released male mosquitoes infected with Wolbachia and reported a significant drop in subsequent mosquitoes: When infected males mate with uninfected wild females, the eggs don't hatch.

Mosquitoes top the ranking of the world's deadliest animals

Mosquitos kill about 760,000 people every year. The vast majority of those deaths are caused by malaria, which is transmitted and spread by the Anopheles mosquito. The second-place deadliest animal title goes to snakes, with an estimated human death toll of around 100,000 annually.

Malaria mosquitoes in a lab were wiped out using CRISPR

Scientists at Imperial College London disabled a gene in female Anopheles gambiae mosquitoes to make them infertile and propagated the infertility mutation at unnaturally high rates using a gene drive. The entire population collapsed within a dozen generations, showing promise for subsequent with mosquitoes in mimicked tropical environments.

Children under 5 account for 76% of all malaria deaths in Africa

The main hypothesis for why the disease hits this age group the hardest is that children this young have still-developing immune systems. Pregnant women and people with HIV/AIDS are also at higher risk of severe infection.

The mosquito's role in the transmission of malaria was confirmed in 1897

The British army doctor Ronald Ross, who later won the Nobel Prize for his work, was the first to describe the transmission of malarial parasites by mosquitoes. He had lab mosquitoes suck blood from malaria-infected people and separately found the malaria parasite inside a mosquito's gut, confirming the bug's role in malaria transmission.

Antimalarials must be taken before traveling to a malaria-endemic area

Malaria prevention involves avoiding getting bitten by mosquitoes (with bug spray and clothing choices) and taking malaria preventative drugs before, during, and after spending time in an area with malaria risk. The drug must be in the blood before the traveler is exposed to malaria parasites.

West Nile Virus is maintained in nature, even without human infections

Mosquitoes pick up the virus when they feed on birds, and then pass it to other birds with their bite, delivering it via virus-laden saliva. Hundreds of different North American bird species can harbor the virus—even if they don't all get sick from it.

Yes, many animals get malaria—not just humans

Birds, rodents, monkeys, lizards, bats, apes, and livestock are among the species that can become infected with malaria. Infected animals' symptoms often resemble those of humans, including fever, lethargy, loss of appetite and difficulty breathing. Birds will also have ruffled feathers and drooped heads.

See this diverse list of vector-borne diseases

Human illnesses caused by parasites, viruses, and bacteria, and transmitted by a living organism—often small, bloodsucking ones like mosquitoes, ticks, and sandflies—are known as vector-borne diseases. That carrier is called a vector. These diseases disproportionately affect the poorest populations in tropical and subtropical areas.

Learn about the basic anatomy of mosquitoes

This short explainer video breaks down the mosquito's general body components, highlighting how mosquitoes breathe, fly, and more. It also touches on how experts can tell different mosquito species apart.

Florida reports 71 imported malaria cases annually—4% of all the US cases

The Sunshine State reports an average of 71 imported malaria cases annually. Malaria isn't endemic to Florida but mosquitoes in the state are biologically capable of transmitting the disease from one infected person to another noninfected person.

The 'kissing bug disease' occurs when a bug's parasite-laden poop gets into your blood

Chagas disease transmission can occur when triatomine bugs bite someone infected with a Trypanosoma cruzi parasite and then bite someone else, passing on the pathogen, though the parasite can also be transmitted in other ways, including via food, congenitally, and through blood transfusions. The bugs tend to feed at night and can bite anywhere on the body, but their reputation for biting people around the mouth and eyes created the idea that the bugs were "kissing" humans. Recent research suggests the disease may be endemic in the US.

Zika virus shocked scientists because the mosquito-borne disease causes birth defects

This revelation, confirmed in 2016, marked the first time that a mosquito-borne disease was known to cause birth defects. Fetuses exposed to the Zika virus during pregnancy sometimes suffer from neurological complications and microcephaly, a small-headed condition associated with neurological development issues and impairment.

'Sloth fever' is an emerging health threat, especially to pregnant women

This disease, caused by the Oropouche virus, is found in animals including sloths, primates, and birds. It primarily spreads through the bite of midges—insects commonly called "no-see-ums." It's endemic to the Amazon region, but US travelers are increasingly contracting it internationally.

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.

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

Flu viruses use special proteins to invade and spread in the body

Influenza viruses carry two key surface proteins: hemagglutinin (H), which lets them enter cells, and neuraminidase (N), which helps them escape and spread. These proteins are the basis for the names of flu subtypes like H1N1 and H3N2

Why are women more likely to suffer autoimmune diseases than men?

A majority of Americans with autoimmune diseases have more than one X chromosome, a typical marker of the female biological sex, according to a study published in February of 2024. During fetal development, cells side with one X chromosome over the other, preventing the overproduction of X-chromosome-specific proteins and shutting down the twin chromosome. This article explores how this X-chromosome inactivation can lead to autoimmune disorders by generating antibodies to the body's own tissues.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

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.

Animal phobias are likely the most common type of phobias, followed by an extreme fear of heights.

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

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

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

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

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.

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.

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.

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

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.

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

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.

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

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.

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.

Hedge funds, the private investment firms that trade a wide swath of financial assets, make money by imposing steep fees on investors and from the fund's investment performance.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Brandi Chastain, the star of the 1999 US victory over China in the 1999 Women's World Cup, was a last-second choice to take the penalty kick that sealed the victory.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by over 1.5 million Muslims.

Up to a million Girl Scouts sell about 200 million cookie boxes every spring, generating $800 million, largely because refusing a child is frowned upon

'Saturday Night Fever,' the 1977 film that introduced disco to the mainstream, was based on a fabricated magazine story.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight