What Attracts Insects to Our Backyard Drinks and Parties?

By Perry Luckett, CoffeeMan1

You’ve been fighting those pesky flies, mosquitoes, and wasps all summer and are ready for a break. But they’re still plentiful through the early fall in many states, especially in those with higher average temperatures, where residents continue their backyard BBQs and parties into November.

By now, you’ve probably worked up a hatred for their insistent hovering and maybe some curiosity about what makes them so attracted to your wine, soda drink, or tender skin. I’m here today to satisfy that curiosity—you’ll have to feed the hatred on your own.

Odor is the key to attraction (at least for bugs)

To keep insects away, we need to understand what attracts them. All flying insects share a love for certain odors, which are key to their attraction, but they have different ways of detecting and homing in on them. For example, uncork a bottle of your favorite Cabernet outside in the summer and odds are high a pesky fruit fly will find your glass by the time you take your first sip.  

These flies navigate using mathematical rules that increase the chance they’ll find your wine. Some even come from as far as a half mile away by using little 90-degree turns to explore an area, flying straight toward a new area, and then doing more 90-degree turns to be sure they’re sniffing out the odor that attracts them. The illustration below shows a fruit fly's surges and re-directions in flight (from bottom to top) when it tracks the odor of alcohol from fermented fruit (or wine) to its source.

Shows a fruit fly's surges and re-directions in flight when it tracks the odor of alcohol from fermented fruit (or wine) to its source.

And the odors they love are strongest in alcoholic and sugary drinks

Why does wine, especially red wine, attract insects so strongly? For the same reason it attracts humans: alcohol, which is the byproduct of fermentation. Fruit flies find this byproduct most readily on over-ripe fruit, whose bruised or torn surfaces enable wild yeasts to

  • attach themselves to exposed sugars (fructose)
  • cause the sugars to ferment
  • convert some of this sugar to alcohol
Fermentation in rotten fruit_Conversion to alcohol.jpg

Fruit flies have very well developed scent receptors that detect the chemical compounds associated with this process. So red wine contains the fruits, sugars, and alcohol that drive them wild. Because other alcoholic drinks, including beer, also use fermentation, and soft drinks have high concentrations of sugar, these flies freak out over all of them.

Common house flies are general feeders: they’ll eat everything from food to animal and human fecal matter. But because of their sponging mouths, they feed only on liquids, which means they must liquefy food through regurgitation. So, although they’re attracted to various substances, the most common items at your backyard party are likely to be sugary drinks or overripe fruit and vegetables, especially after they’ve sat out in the sunshine for a while.

A common thread: mosquitoes like alcohol too

Flies can irritate us with their buzzing about, but mosquitoes seem to really have it in for us.  Are they also attracted to the sugar and alcohol in drinks, or do they (like zombies) crave human flesh? Turns out, it’s a bit of both, and these attractors make it difficult to keep mosquitoes away.  A fertile combination of odors, body heat, moisture, and chemical compounds exuded from the skin make certain folks more susceptible to bug bites than others. (TheWeek.com, July 15, 2013)

Consuming alcohol may make your blood tastier to mosquitoes.  Researchers discovered the alcoholic equivalent of three cans of beer can lead to 30 percent more bug bites, at least for men in a controlled laboratory setting.   Mosquitoes also feed on fermenting fruit, and a special enzyme that helps them break down alcohol before it hits the nervous system might allow them to drink you, a much-larger creature, under the table.

So how do we keep mosquitoes away?  Limit what attracts them. The more alcohol you drink at the BBQ, the more likely you are to get bitten. (Worth it, you say?)  Open sugary and alcoholic drinks at backyard parties attract mosquitoes into the area around you.  The insects then use other attractors, such as people with type O blood or larger physiques, to zero in on their intended victims.


And then come wasps and yellow jackets: aggressive bullies to the BBQ

Ok, that title is a bit of a bad rap.  During the late summer and early fall, these stinging insects focus on getting food from any source to care for their colonies.  But their appetite for sugary sweets, such as soda, fruit, and candy, is what makes them so aggressive at outdoor parties, where their favorite foods are laid out for them to enjoy.  Their aggression causes them to sting thousands of Americans and even kill those who have allergic reactions or suffer anaphylactic shock.


Every year wasps and yellow jackets start brand new colonies and spend most of their time caring for eggs, larvae, and pupae—which don’t fly around like the adults looking for sweets. But by the end of the summer, a colony may have as many as 1,000 workers, all of whom seek to satisfy their insatiable craving for sweets. To keep these aggressive insects away and avoid their stings, don’t

  • walk or mow unaware over nests
  • wear strong sweet perfumes or cologne
  • wave your arms about when they approach
  • drink from open sugary drink cans, bottles and cups without checking them first
  • leave open containers of food on your picnic table—especially with cupcakes or candy inside

How do you limit insect invaders at your party?

Smokers, bug lights, and DEET or other insect repellants on your skin will certainly discourage insects from ruining your party.  But you also can limit their effects on your food sources. Tightly cover and seal food you bring outdoors, then emphasize resealing containers as you dish foods out to your guests.  

Also, find a good cup, glass, or can cover for your drinks—such as the Kup Kap™ from Koffee Kompanions. This Thinsulate-insulated cup cover comes in two sizes to cover wine glasses, cups, mugs, glasses, and small or large bowls.


Do you have other ideas for our readers? Please share them in the Comments section below.

Perry LuckettComment