This article was medically reviewed by Shonda Hawkins, MSN, a nurse practitioner and member of the Prevention Medical Review Board, on June 11, 2019.
It’s backyard barbecue season—but you’re not the only one planning a feast. The mosquitos are out and ready to chow down. But before you fill another shopping bag with citronella candles, it’s important to understand your adversary.
When a mosquito lands on your skin, it will feed on your blood—but once it leaves, the proteins in its saliva stay behind. Your immune system sees this is a threat and pumps out histamine (the same response it has to allergens) to attack these proteins. The result? Those unbearably itchy, red welts you remember scratching at as a kid. Luckily, there are ways to get rid of a mosquito bite quickly, and the itching should go away within two to three days.
But it’s not just bites you need to worry about—the aftermath can be unpleasant, too. Mosquitos can carry all sorts of intense diseases, like the West Nile or Zika viruses, or even chikungunya and malaria (which are risks if you travel to certain countries). That’s why preventing mosquito bites in the first place should be a priority during the warmer months.
Entomologists know how these insects operate, which is why we consulted several for the dos and don’ts of repelling these pesky pests.
Almost any breeze—anything above 1 MPH—makes it very difficult for mosquitoes to fly, says Jonathan Day, PhD, a mosquito expert and professor of medical entomology at the University of Florida. If you can pick a breezy spot for your summer outing, that can help prevent mosquito bites.
Plug-in fans are also a great deterrent, he adds. Just keep the flow of air directed at the lower half of your body; mosquitoes tend to fly very close to the ground to avoid wind, so directing the fan’s force downward will block their approach.
Natural wind or a fan will work much more in your favor than those fancy, ultrasonic devices and apps marketed as mosquito repellants—some of which claim to mimic the sound of dragonflies. “They don’t work at all,” Day says.
Just like you, mosquitos crave a meal during certain times of day, says Howard Russell, an entomologist at Michigan State University. And for these critters, it’s often around dusk and dawn.
That’s because the wind typically dissipates as the sun rises and sets, which brings mosquitoes out to feed, Day explains. If you can try to stay inside during these times when the weather is warm, you’ll be able to prevent more than a few mosquito bites.
DEET has a bad reputation, but adverse reactions to it are rare—and tend to occur only when people swallow or snort the stuff. When used as directed, it’s extremely effective, since it blocks a mosquito’s CO2 receoptors, Day says. Still, he’s quick to add: “Most people don’t understand how to apply it properly.” (Fun fact: DEET makes a great tick repellent, too.)
First, you should not spray DEET on your body and clothes like it’s perfume, he stresses. Instead, squirt a little onto your hands and rub it onto your ankles, elbows, wrists, forehead, and all the other places where your skin is thin—and where mosquitoes love to feed.
Also important: Day says a product’s DEET concentration determines how long it will last—not how well it will work. If you’ll be outside for 90 minutes or less, he says a product with 7 to 10 percent DEET will do the job, and you can always reapply to extend its efficacy (do not go higher than 30 percent). DEET in lotion or wipe form is also just as effective as a spray and removes the risk of inhaling it.
Finally, don’t waste your money on wearable DEET items, like wristbands or anklets—they don’t actually prevent mosquito bites, says Day.
If you just can’t with DEET, there are other options that are recommended by the Centers for Disease Control and Prevention (CDC) for use in repelling mosquitos, including:
While all of the above have been found to be effective like DEET, Pereira recommends using picaridin. “This is something that was developed for the military just like DEET was,” he says. “It works really well.”
If you’re at the store and you’re not sure if a repellent has these ingredients, “your safest bet is to look for Environmental Protection Agency approval on the product’s label,” says Nancy Troyano, PhD, a board-certified entomologist with Ehrlich Pest Control. If it does, it should be effective and safe. (You can also search products registered with the EPA here.)
This can be easier said than done in the summer, but mosquitos are drawn in by pheromones released in your sweat, says Roberto M. Pereira, PhD, an entomologist and research scientist at the University of Florida.
This can vary from person to person. “Some people, like me, attract mosquitoes regardless of what they drink, eat, or wear,” says Russell. Still, the more you can do to take it easy on the sweating—especially during peak mosquito hours—the better.
Mosquitoes can’t penetrate clothing that has a very tight weave, Day says. While cotton and linen typically aren’t great armor against mosquito bites, Day says many synthetic fibers—particularly high-tech athletic apparel—tend to be woven tightly enough to keep bugs out. Any garment that offers sun protection will also have a tight enough weave to prevent mosquito bites, especially when you opt for long sleeves and pants.
Mosquitoes also use their vision to search for food sources during the daylight hours. Since they fly very close to the ground, they tend to find targets by looking for things that contrast with the horizon, Day says. “Dark colors stand out, but light colors are less attractive to them,” he adds. Of course, make sure you protect any exposed areas with a repellent if you’re going to be spending time outdoors for a long period of time.
Day says carbon dioxide (CO2) is the primary thing mosquitoes search for to identify food sources. And when your heart rate is elevated, your body produces more CO2. From exercise to drinking alcohol to eating spicy foods, anything that cranks up your metabolic rate will increase your CO2 production—and make you irresistible to mosquitoes, Day says. Unfortunately, being overweight or pregnant can also up your CO2 output, he adds.
If you’re outdoors and you know your heart rate will be spiking, make sure you wear protective clothing or apply a repellent to keep bug bites at bay.
There are different types of mosquitos, and the “mosquitos that we worry about in urban areas are usually ones that are being produced in your own backyard,” Pereira says. Aedes mosquitos, which transmit Zika virus and chikungunya, can easily breed in small containers of water like a birdbath or even water sitting around your plants. “They can breed in your own yard, and you wouldn’t necessarily know it,” Pereira says.
Do your best to clear out any standing water to lower the odds that you’ll have lots of mosquitos hanging around your place ready to bite.
This shouldn’t be your only mosquito-combating strategy, but Pereira says that certain plants may help discourage mosquitos from hovering near your house. Those include things like citronella, lavender, lemongrass, marigolds, and basil. “If you had enough, it could make a difference in terms of mosquitos inside your property,” he says.
Just keep realistic expectations about what these can and can’t do, Troyano says. While they may help tamp down on the number of mosquitos around your place, “even planted in large quantities, the potency of these plants would not be enough to keep mosquitoes out of your yard entirely,” she says.
The same goes for citronella candles and oils. While they’re natural insect repellents, Day says they only work if their scent or smoke gets between you and the mosquito. So if you’re lighting tiki torches that sit a few feet off the ground, they won’t do much to prevent mosquito bites, he says.
If you live in an area where the mosquitos are unbearable, it might be worth hiring a professional to come and treat your yard with insecticide, Russell says. This can do a pretty good job of ensuring they won’t come anywhere near your place.
As for mosquito traps? They’ve been souped up with fancy features to attract mosquitoes with special lights, heats, or scents. “There’s no doubt that traps can—under the right environmental conditions—capture of a lot of mosquitoes,” Day says. Realistically, though, you can’t catch ‘em all. “Over the last 30 years, there have been many traps marketed as being able to clear a one-acre or five-acre lot,” Day says, “and it has never been my experience, even with very efficient traps, that they can rid a whole area of mosquitoes.”
A trap in the middle of your backyard will kill mosquitoes that fly close enough to sense its lures, sure, he says, but countless more will come flying into your yard to fill the space they leave behind. Mosquitoes are also adept at telling the difference between a trap and a living, breathing host—aka you.
This can be tough, but it’s definitely worth a try if mosquitos are terrible in your area. “Any scented perfume, lotion, or soap could potentially attract mosquitoes,” Troyano says. “If you want to reduce your attractiveness to mosquitoes, avoid scented products in general.”