10 Facts About Argentine Ants

A pile of genetically-related Argentine ants
A pile of genetically-related Argentine ants
Marc Matteo, Flickr // CC BY-NC 2.0

A supercolony of invasive Argentine ants (Linepithema humile) stretches for 560 miles beneath California, from San Diego to San Francisco. The billions of Argentine ants are unlike other ants in many ways—and they are virtually indestructible. Along with their supercolonies in Europe, Japan, and Australia, L. humile’s global domination is rivaled only by that of human beings. Here’s what you should know about these prolific pests.

1. Argentine ant colonies are ruled by hundreds of queens.

Most ant colonies revolve around a single queen. Growing much larger than the worker drones, she is programmed to mate as quickly as possible, then to leave her nest of origin and establish a new one. In some species, a single queen can lay millions of eggs in a lifetime, producing an army of worker drones and future queens who will go off to build their own nests. But unlike most ants, Argentines are polygynous: Each nest contains multiple queens. In some, they can form up to 30 percent of the population.

2. Argentine ants move their nests frequently.

Nest types vary from ant species to ant species, but those who live in soil commonly dig tunnels and chambers deep into the earth that will protect the colony throughout the life of the queen. L. humile, though, is transient and ever shifting. Argentine ants frequently pack up their eggs and move the entire colony, queen and all, to a new nest, even when there is no apparent threat. Biologist Deborah Gordon told Ars Technica that the ants typically have 20 to 30 shallow nests at any one time, which can be built up in a matter of just weeks.

3. Argentine ants traveled the U.S. before settling down in California.

Argentine ants arrived in the United States from Northern Argentina in the late 19th century, when the first recorded Argentine ant was found in Louisiana in 1891. Researchers believe that the ants hitched a ride to North America in Argentinian shipments of coffee or sugar off-loaded at the Port of New Orleans. From there, they traveled—most likely by train—across the South and into California. Enticed by the Mediterranean climate, one similar to that of its original home in South America, the ants set up shop. By 1907, they’d displaced local native ants and begun their first steps towards total soil domination along 560 miles of California coastline.

4. California’s Argentine ants are more laid-back than their South American cousins.

In side-by-side comparisons of Argentine ants from their South American homeland and California, researchers have found that those from the West Coast are far more mellow than those from Argentina. In studies, it was typical for two ants from different nests to fight when placed in the same vial in Argentina, but in California, ants from different nests rarely fought, even when they were collected from locations several hundred miles apart.

A DNA study of ants from both locations in 2000 revealed a stark difference. In the ants from Argentina, microsatellites—short, uniquely patterned DNA sequences passed down from generation to generation—had more than twice as much variation as the microsatellites of the Californian ants. When two individuals from different nests in California were placed together, they recognized one another as family. The ants from Argentina didn’t, making them more likely to display territorial aggression.

The difference is rooted in the genetic bottleneck the ants encountered on their arrival to the Golden State over a century ago. According to biologist Neil D. Tsutsui, who conducted the DNA study, the ants in California today are all descendants of that founding colony. “It would be as if all of the people in the United States were descended from the Pilgrims who came here in 1620,” he told the Stanford Report in 2004. Instead of competing with one another, generation after generation has worked together to take out native ants and build an immense California colony.

5. Argentine ants protect other insects in exchange for sweet, sweet honeydew.

Two Argentine ants share a tiny blob of honeydew.Davefoc, Wikimedia Commons // CC BY-SA 4.0

Argentine ants love to feed on sweet nectar, but flowers and suburban kitchens aren’t the only source of such desirable foodstuffs. Insects that feed on plant sap, like mealybugs, scales, and aphids, naturally excrete sugar-rich liquid “honeydew” from their butts. To secure a steady flow of the sticky-sweet substance, Argentine ants will fight off the predators of their insect chefs, including soldier beetles and midges. They’ll even relocate their honeydew producers to better food sources or microclimates to get the most they can out of their anal secretions.

6. The California Argetine ant supercolony is one-sixth the size of Southern Europe’s.

The California supercolony, which scientists have named the “Californian large,” is only the second-biggest conglomeration of Argentine ants in the world. The biggest colony is found along Southern Europe’s Mediterranean coast, where it stretches 3700 miles from northern Italy to the Atlantic coast of Spain. The ants, introduced around 80 years ago, now number in the billions. Smaller supercolonies also exist in Japan and Australia.

7. Argentine ants are second only to humans in their scale of world domination.

In 2009, researchers discovered that Argentine ants from three of the world’s largest supercolonies (Southern Europe, California, and Japan) are so closely related that they actually form a single mega-colony. The study, led by Eriki Sunamura from the University of Tokyo, found that when placed together, ants from the three supercolonies refused to fight. Instead, they rubbed antennae in greeting the way L. humile does when interacting with genetically-related individuals.

The researchers believe that the Argentine ant mega-colony isn’t just the largest insect colony ever identified; it rivals that of human colonization around the globe. Presenting their findings in the journal Insect Sociaux, they wrote, “the enormous extent of this population is paralleled only by human society.”

8. A mass execution of Argentine ant queens takes place every spring.

Each spring, just before mating season begins, worker ants go on a killing rampage and assassinate 90 percent of their queens. Entomologists aren’t sure exactly why the large-scale execution occurs, but one hypothesis, published in the Journal of Evolutionary Biology in 2001, suggests that it is a “spiteful behavior” to kill the queens that are less related, on average, to the workers.

In their study, researchers from the University of Lausanne hypothesized that Argentine ants are regularly separated from direct family members through free exchange among the nests. Before mating season begins each year, those that are genetically related band together to kill more distantly related queens. Doing so decreases the nest’s genetic diversity and allows it to be rebuilt with a queen who is directly related to the greatest majority of workers.

The study’s results were inconclusive and the question remained unanswered, yet researchers learned something unexpected in the process. Instead of finding genetic diversity among worker ants, those belonging to each nest were actually a homogenous population. Only the queens were genetic outliers with relatively few familial relationships in each nest.

9. Climate change is making Argentine ants more of a nuisance to humans.

Argentine ants thrive in a Mediterranean climate where winters are cool and wet and summers are warm and dry. When conditions are ideal, they largely keep to themselves, but when conditions are drought-like or extremely wet, the ants move indoors in search of more hospitable climes. Experts at survival, Argentine ants can find food or water that’s been left unguarded in just minutes.

With the climate crisis, conditions in California are becoming more extreme. Hot days, no longer relegated just to the summer months, are becoming more numerous and prolonged. Droughts are becoming more frequent. While these changes are unlikely to harm much of the California supercolony, they are likely to drive the residents of urban nests more frequently into people's homes, making the ants a major nuisance for residents from San Diego to San Francisco.

10. Argentine ants are almost impossible to eradicate.

Individual Argentine ants are easy enough to kill, but an Argentine ant colony is a different story. The California colony has no natural predators and, thanks to their high levels of cooperation and massive numbers, L. humile has effectively destroyed possible competitors and disrupted the ecological balance of native species in the process. Insecticides, which are unable to penetrate into the underground nests, aren’t particularly effective. And because the ants can pick up and move their entire nest so quickly, neither are household control measures such as ant bait. After just over a century in California, Argentine ants are now virtually invincible.

The 10 Best Air Fryers on Amazon

Cosori/Amazon
Cosori/Amazon

When it comes to making food that’s delicious, quick, and easy, you can’t go wrong with an air fryer. They require only a fraction of the oil that traditional fryers do, so you get that same delicious, crispy texture of the fried foods you love while avoiding the extra calories and fat you don’t.

But with so many air fryers out there, it can be tough to choose the one that’ll work best for you. To make your life easier—and get you closer to that tasty piece of fried chicken—we’ve put together a list of some of Amazon’s top-rated air frying gadgets. Each of the products below has at least a 4.5-star rating and over 1200 user reviews, so you can stop dreaming about the perfect dinner and start eating it instead.

1. Ultrean Air Fryer; $76

Ultrean/Amazon

Around 84 percent of reviewers awarded the Ultrean Air Fryer five stars on Amazon, making it one of the most popular models on the site. This 4.2-quart oven doesn't just fry, either—it also grills, roasts, and bakes via its innovative rapid air technology heating system. It's available in four different colors (red, light blue, black, and white), making it the perfect accent piece for any kitchen.

Buy it: Amazon

2. Cosori Air Fryer; $120

Cosori/Amazon

This highly celebrated air fryer from Cosori will quickly become your favorite sous chef. With 11 one-touch presets for frying favorites, like bacon, veggies, and fries, you can take the guesswork out of cooking and let the Cosori do the work instead. One reviewer who “absolutely hates cooking” said, after using it, “I'm actually excited to cook for the first time ever.” You’ll feel the same way!

Buy it: Amazon

3. Innsky Air Fryer; $90

Innsky/Amazon

With its streamlined design and the ability to cook with little to no oil, the Innsky air fryer will make you feel like the picture of elegance as you chow down on a piece of fried shrimp. You can set a timer on the fryer so it starts cooking when you want it to, and it automatically shuts off when the cooking time is done (a great safety feature for chefs who get easily distracted).

Buy it: Amazon

4. Secura Air Fryer; $62

Secura/Amazon

This air fryer from Secura uses a combination of heating techniques—hot air and high-speed air circulation—for fast and easy food prep. And, as one reviewer remarked, with an extra-large 4.2-quart basket “[it’s] good for feeding a crowd, which makes it a great option for large families.” This fryer even comes with a toaster rack and skewers, making it a great addition to a neighborhood barbecue or family glamping trip.

Buy it: Amazon

5. Chefman Turbo Fry; $60

Chefman/Amazon

For those of you really looking to cut back, the Chefman Turbo Fry uses 98 percent less oil than traditional fryers, according to the manufacturer. And with its two-in-one tank basket that allows you to cook multiple items at the same time, you can finally stop using so many pots and pans when you’re making dinner.

Buy it: Amazon

6. Ninja Air Fryer; $100

Ninja/Amazon

The Ninja Air Fryer is a multipurpose gadget that allows you to do far more than crisp up your favorite foods. This air fryer’s one-touch control panel lets you air fry, roast, reheat, or even dehydrate meats, fruits, and veggies, whether your ingredients are fresh or frozen. And the simple interface means that you're only a couple buttons away from a homemade dinner.

Buy it: Amazon

7. Instant Pot Air Fryer + Electronic Pressure Cooker; $180

Instant Pot/Amazon

Enjoy all the perks of an Instant Pot—the ability to serve as a pressure cooker, slow cooker, yogurt maker, and more—with a lid that turns the whole thing into an air fryer as well. The multi-level fryer basket has a broiling tray to ensure even crisping throughout, and it’s big enough to cook a meal for up to eight. If you’re more into a traditional air fryer, check out Instant Pot’s new Instant Vortex Pro ($140) air fryer, which gives you the ability to bake, proof, toast, and more.

Buy it: Amazon

8. Omorc Habor Air Fryer; $100

Omorc Habor/Amazon

With a 5.8-quart capacity, this air fryer from Omorc Habor is larger than most, giving you the flexibility of cooking dinner for two or a spread for a party. To give you a clearer picture of the size, its square fryer basket, built to maximize cooking capacity, can handle a five-pound chicken (or all the fries you could possibly eat). Plus, with a non-stick coating and dishwasher-safe basket and frying pot, this handy appliance practically cleans itself.

Buy it: Amazon

9. Dash Deluxe Air Fryer; $100

Dash/Amazon

Dash’s air fryer might look retro, but its high-tech cooking ability is anything but. Its generously sized frying basket can fry up to two pounds of French fries or two dozen wings, and its cool touch handle makes it easy (and safe) to use. And if you're still stumped on what to actually cook once you get your Dash fryer, you'll get a free recipe guide in the box filled with tips and tricks to get the most out of your meal.

Buy it: Amazon

10. Bella Air Fryer; $52

Bella/Amazon

This petite air fryer from Bella may be on the smaller side, but it still packs a powerful punch. Its 2.6-quart frying basket makes it an ideal choice for couples or smaller families—all you have to do is set the temperature and timer, and throw your food inside. Once the meal is ready, its indicator light will ding to let you know that it’s time to eat.

Buy it: Amazon

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A Two-Toed Sloth Accidentally Hitched a 40-Mile Ride in a Truck's Engine Bay

Tony Hisgett, Wikimedia Commons // CC BY 2.0
Tony Hisgett, Wikimedia Commons // CC BY 2.0

Most sloths move at a maximum speed of 6 to 8 feet per minute, but one two-toed sloth in Costa Rica shattered that pace on a recent joy ride. As Jalopnik reports, the female sloth traveled 40 miles after sneaking into a truck’s engine bay undetected.

The vehicle's drivers noticed something was out of place when they stopped to check the engine and saw a tuft a fur. They reached out to Toucan Rescue Ranch, a wildlife rehabilitation center near San Jose, which identified the stowaway as a two-toed sloth. Though it had been on board for over an hour, the animal managed to survive the road trip unscathed.

The animal caretakers at TRR dubbed the sloth Lola la Trailera, or "Lola the Truck Driver," after the 1983 Mexican action movie of the same name. She was exhausted and aggressive when she arrived at the center, but after feeding her a diet of Pedialyte, wild leaves, and steamed veggies, the caretakers were able to restore her to full health. She was returned to the forest she originated from following six days of rehabilitation.

A sloth's usual lack of speed isn't a sign of laziness—it's a survival tactic. Fat and protein are limited in the rainforest canopies where sloths reside, so they must conserve energy by limiting their activity. But as Lola la Trailera proved, sloths have the potential to move much faster with a little assistance.

[h/t Jalopnik]