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. Jonathan Day, PhD, a mosquito expert at the University of Florida, knows how these insects operate. Here, he explains the dos and donts of repelling these pesky pests.

Do: Blow them away
Almost any breeze—anything above 1 MPH—makes it very difficult for mosquitoes to fly, Day says. If you can pick a breezy spot for your summer outing, that works. Plug-in fans are also a great deterrent, he adds. Just keep the flow of air directed at the lower half of your body; mosquitos tend to fly very close to the ground to avoid wind, so directing the fan's force downward will block their approach. (Check out why mosquitoes love your particular blood type.)

Don't: Waste money on citronella candles and coils
citronella
While citronella and other oils are natural insect repellants, Day says they only work if their scent or smoke gets between you and the mosquito. If you're lighting tiki torches that sit a few feet off the ground, they won't do much to keep the bugs at bay, he says. Even if you're surrounded by citronella candles or coils, Day says he seriously doubts they'd be effective.


Do: Give your heart a breather
Day says carbon dioxide (CO2) is the primary thing mosquitos search for to identify food sources. And when your heart rate is elevated, your body produces more CO2. From exercise to drinking alcohol or eating spicy foods, anything that cranks up your metabolic rate will increase your CO2 production—and make you irresistible to mosquitos, Day says. (Unfortunately, being overweight or pregnant can also up your CO2 output, he adds.)

Don't: Swallow a particular food or supplement
You may have heard eating bananas, garlic, or supplements with B-vitamins can repel mosquitos. But Day says none of these will do you any good.

Do: Buy tightly woven duds
Mosquitos can't penetrate clothing that has a very tight weave, Day says. While cotton and linen typically aren't great armor against bug bites, Day says many synthetic fibers—particularly high-tech athletic apparel—tend to be woven tightly enough to keep mosquitos out. Any garment that offers sun protection will also have a tight enough weave to block bites.

Don't: Rely on ultrasonic devices
There are many ultrasonic devices and phone apps marketed as mosquito repellants—some of which claim to mimic the sound of dragonflies. "They don't work at all," Day says.

Do: Wear these colors
light colors
Mosquitos use their vision to search for food sources during the daylight hours. And 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.


Don't: Rub mouthwash on your skin
mouthwash
Some people say Listerine can repel mosquitos because mouthwash contains eucalyptol, which is also found in some bug repellants. Triclosan, another mouthwash ingredient, has also been linked to malaria prevention. But research shows slathering yourself in mouthwash won't do much to ward off mosquitos.

Do: Rub on some DEET
DEET has a bad reputation. But peruse the medical literature, and you'll find adverse reactions to it are rare—and tend to occur only when people swallow or snort the stuff. Like anything you rub on your skin, DEET can cause an allergic reaction in some people. But used as directed, it's basically harmless and extremely effective, Day says. But he's quick to add, "Most people don't understand how to apply it properly."

First of all, 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 mosquitos 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% DEET will do the job, and you can always reapply to extend its efficacy. DEET in lotion- or wipe-form is just as effective as a spray—and those remove the risk of inhalation.

Don't: Buy wristbands or other wearable DEET items
Day says DEET works by blocking a mosquito's CO2 receptors. That happens when a mosquito lands on your skin and comes into contact with the DEET. "They'll still land on you if you apply it," he says, "but they won't bite." Because DEET isn't a scent-based repellent, any form of it that isn't spread on you skin won't work. So skip the wristbands, anklets, and other bogus DEET wearables, Day advises.

Do: Avoid the mosquitos' peak hours
peak hours
Every boater knows big water tends to die down at dawn and dusk. That's because the wind typically dissipates as the sun rises and sets. The lack of wind at those times also brings mosquitos out to feed, Day explains. If you can schedule your outdoor outings at other times of the day, you'll sidestep a lot of bugs.