The crowd at G Street Wunderbar passed around two vials filled with water. They held them up to the bar’s dusky, neon lights, some guffawing and others blanching as they eyed the specimens.
Inside the vials, tiny mosquito larvae and pupae flittered about frenetically, each tube a congregation of either whitish or brownish specks.
“Juvenile mosquitoes are aquatic and if you have standing water in your yard, mosquitoes will lay eggs there and then you’ll get larvae and pupae,” said Lisa Baik, an assistant professor in the Department of Entomology and Nematology at UC Davis who presented at the January 2026 Davis Science Café, a free event hosted by the Department of Chemistry.
“When in doubt, dump it out,” she said of standing water.
If you’re reading this, chances are you’ve been bit by a mosquito. But what do you know about these creatures beyond them being perceived pesky annoyances?
How about this: did you know there are over 3,000 species of mosquitoes? Or that while they mostly thrive in tropical environments, some live in the desert and Arctic. What about the fact that only a small percentage of those species feed on humans, and even fewer are disease vectors?
Despite this, mosquitoes are the world’s deadliest animal, causing an estimated 725,000 human deaths each year.
“When we talk about mosquitoes being bad, they’re not bad on their own. It’s actually the fact that they can carry different pathogens that cause diseases,” said Baik, noting that vector-borne diseases account for 17% of all diseases globally. “And of course, with human movements, we have mosquitoes moving around the world and we also have pathogens moving around different parts of the world.”
“That’s happened quite a bit historically — actually, many, many, many times, which is fascinating — and in some cases, it’s actually shaped human history,” she added.
Why are mosquitoes attracted to humans?
The credo of the Baik Lab is to “fight the bite.” Their research primarily focuses on the Asian tiger mosquito (Aedes albopictus), a particularly invasive species that carries the pathogens responsible for Zika, yellow fever and dengue fever, among others. Native to Southeast Asia, the species has prolifically spread to Europe, Africa, South America and North America, including California.
“They truly are global,” said Baik, who graduated from UC Davis with a bachelor of science degree in neurobiology, physiology and behavior and a bachelor of arts degree in psychology in 2011. “They are invasive, yet they’re severely understudied.”
Baik and her colleagues specifically study what leads mosquitoes to bite their prey.
How taste influences mosquito biting behavior
While mosquitoes use various senses to detect humans, Baik is interested in the role taste plays in this decision-making process. What makes a mosquito, when it lands on a human, likely to bite? And what deters it?
In a study published in 2024 in Nature, Baik and colleagues showed how “different tastes are encoded by neurons in mosquitoes and how they influence biting, feeding and egg-laying,” Yale News reported. They also revealed “compounds in human sweat that increase biting behavior…as well as bitter compounds that suppress egg-laying and feeding behaviors.”
The research revealed that a combination of salt and certain amino acids, both produced by human skin, led to an increase in biting behaviors. When presented to mosquitoes separately, they had no influence on biting behavior.
“We were able to identify key compounds that are on the human skin surface that actually makes mosquitoes bite more,” Baik said. “This was a question that we didn’t quite have figured out in the field prior.”
What attracts mosquitoes? Common triggers explained
What leads a mosquito to bite is a complex question. Baik said that humans likely taste differently from individual to individual. Diet and blood type are thought to play roles, but narrowing down the specifics is a difficult task.
What’s known is that mosquitoes are attracted to the carbon dioxide we exhale, using it as a cue to find us. Additionally, not showering for a few days or emitting copious amounts of body odor are other attractants.
“Fun fact, Limburger cheese has this odor and mosquitoes (are) attracted to it,” Baik said. “It turns out it’s because it smells like our feet. Same odorant, same compound.”
Since mosquitoes smell us out, Baik recommended showering to deter their nibbling tendencies.
Dark colors also attract mosquitoes since they are easily identifiable to mosquito vision, which relies on color contrast.
“One of the recommendations that I make is to wear light-colored clothing, also maybe long sleeves if you’re hiking towards sunset time, when mosquitoes are really active,” Baik said. “That can quite literally prevent biting.”
How to prevent mosquito bites
Insecticides and repellents are our primary form of defense against mosquitoes. These products, however, come with a host of negative side effects. A study found that insecticides that use pyrethroids harmed or killed monarch caterpillars up to three weeks after spraying.
“It’s meant to kill something, right? So it does have quite adverse effects,” Baik said. “The other thing is that with something like this, evolution always fights back.”
Mosquitoes, including the Asian tiger mosquito, are increasingly developing insecticide resistance. Pair that with the negative effects of insecticides on pollinators, and it’s a lose-lose situation.
“Because insects are growing resistant to insecticides, some actually estimate that within the next few decades we’re going to run out of options of insecticides,” Baik said.
New research on mosquito repellents and bite prevention
Preventing bites is where Baik and her lab’s research on taste cues come into play. They’re currently exploring the efficacy of a specific family of compounds that shows promise as repellents.
To show this, Baik screened two videos for the audience at G Street Wunderbar. In one video, a human arm is shown being feasted upon by a swarm of mosquitoes. In the next video, a human arm treated with their compounds of interest shows mosquitoes flying around, landing on the arm and then quickly flying away without biting.
“We’ve tested it for now up to eight hours,” she said. “It’s actually outperforming our best gold standard that we have out there.”
The Davis Science Café is held every second Wednesday of the month. Learn more about the Davis Science Café.
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