30 Fascinating Facts About Marilyn Monroe

Keystone Features/Getty Images
Keystone Features/Getty Images

Marilyn Monroe was born on June 1, 1926. Had she not passed away in 1962 at the age of 36, what might she be doing now? Would she have continued acting? Become Mrs. Joe DiMaggio for the second time, as he claimed? Carved out an Oscar-winning career for herself? What could have been remains a mystery, much like Monroe herself. But here are some facts we do know.

1. Norma Jeane Baker's first marriage was arranged.

Portrait of a young Marilyn Monroe
Sotheby's/Getty Images

As a child, Norma Jean Baker (originally spelled as Norma Jeane) was in and out of foster homes, state care, and the guardianship of various family friends. She never knew her father, and her mother had been committed to a psychiatric facility. A 15-year-old Baker had been staying with family friend Grace Goddard, but they decided to move to West Virginia, and couldn’t take Baker. Unless she married, the teenager would have been turned back over to an orphanage. So they turned to 20-year-old James Dougherty next door and suggested a marriage. "I thought she was awful young," he later said, but "we talked and we got on pretty good." They were married just 18 days after she turned 16.

2. Norma Jean Baker was named after a movie star.

Norma Jean Baker's mother had fame on the brain early on for her daughter. She chose "Norma" as her first name after actress Norma Talmadge.

3. “Marilyn Monroe” wasn’t her first choice for a stage name.

If Norma Jean Baker had gone with her first choice of stage name, "Jean Adair" would be the household name today. According to Baker's sister, Baker's original stage name of choice played off of Norma Jeane, her real name.

4. "Monroe" was the maiden name of Marilyn Monroe's mother.

Baker chose Monroe as her surname because it was her mother's maiden name. In her ghost-written autobiography, Monroe said she was told that she was somehow related to President James Monroe, but no evidence has ever been found to support that. "Marilyn" came from a studio executive who thought she resembled Marilyn Miller, an actress who died at the age of 37 (Monroe was 36 when she passed away).

5. When Gladys Baker told people she was Marilyn Monroe’s mother, no one believed her.

Marilyn Monroe in June 1949.
Marilyn Monroe in June 1949.
Hulton Archive/Getty Images

When Gladys Baker, Marilyn's mother, told people Marilyn Monroe was her daughter, no one believed her. Gladys, once a film cutter at RKO, was diagnosed with bipolar disorder and was in and out of psychiatric care for years. Gladys took Norma Jean to a foster family when she was just two weeks old, which resulted in a series of orphanages and foster care homes for the rest of her childhood—so she didn’t have a close relationship with her mother. When Marilyn hit it big and Gladys told friends and co-workers that her daughter was the Marilyn Monroe, they dismissed it as one of her paranoid schizophrenic delusions.

6. Marilyn Monroe often referred to "Marilyn Monroe" in the third person.

Actor Eli Wallach once recalled that Monroe seemed to flip an inner switch and turn "Marilyn" on and off. He had been walking on Broadway with her one evening, totally incognito, and the next minute, she was swarmed with attention. "'I just felt like being Marilyn for a minute,'" Wallach remembers her saying. Photographer Sam Shaw often heard her critiquing "Marilyn's" performances in movies or at photo shoots, making comments like, "She wouldn't do this. Marilyn would say that."

7. Marilyn Monroe was Truman Capote's first choice to play Holly Golightly in Breakfast at Tiffany's.

Truman Capote had Monroe in mind for the lead role in Breakfast at Tiffany's—and she even performed two scenes for him. "She was terrifically good," Capote later said. In the end, she didn't take the part because her advisor and acting coach didn't think it was the type of character she should be playing. Either way, Capote wasn't at all thrilled with the studio's choice of Audrey Hepburn, saying, "Paramount double-crossed me in every way and cast Audrey."

8. Marilyn Monroe reportedly hated being in front of the camera.

After working with Monroe on Bus Stop, Oscar-nominated actor Don Murray noted that while her talent was undeniable, she was never fully comfortable in front of the camera. “She was a very experienced film actress, but she could forget so many of the mechanical techniques. She would constantly miss her marks, so she would be out of focus or out of the light or in a shadow,” Murray said. “I think it was a lack of confidence. For somebody who the camera loved, she was still terrified of going before the camera and broke out in a rash all over her body.”

9. Marilyn Monroe's on-camera glow wasn't exactly natural.

Before her makeup was applied, Marilyn slathered on a layer of Nivea Creme or Vaseline, believing it made her look more luminous on film. And she tried to stay out of the sun. “Despite its great vogue in California, I don’t think suntanned skin is any more attractive ... or any healthier, for that matter," Monroe once said. "I’m personally opposed to a deep tan because I like to feel blond all over.”

10. Marilyn Monroe had a thing for intellectual men.

Marylin Monroe waves to the camera with husband Arthur Miller on her arm in 1958.
Marylin Monroe waves to the camera with husband Arthur Miller on her arm in 1958.
Votava/Imagno/Getty Images

Monroe's marriage to writer Arthur Miller probably tells you that, but there's more evidence. Monroe was once roommates with actress Shelley Winters, who said they made a list of men they wanted to sleep with, just for fun. "There was no one under 50 on hers," Winters later reported. "I never got to ask her before she died how much of her list she had achieved, but on her list was Albert Einstein, and after her death, I noticed that there was a silver-framed photograph of him on her white piano."

11. Marilyn Monroe was loyal to Arthur Miller, even thought it put her career in jeopardy.

In 1956, Marilyn’s future husband—The Crucible playwright Arthur Miller—was called to testify before the House Un-American Activities Committee. When this happened, celebrities were expected to name names of people who had allegedly been involved in Communist activities. Miller refused to do so, which could have landed him in prison. Marilyn’s steadfast commitment to Miller probably kept the playwright from being sentenced. (It probably didn’t hurt that he announced their wedding plans in the middle of his testimony.)

12. The FBI had a file on Marilyn Monroe.

The FBI's file on Monroe was probably opened due to her relationship with Miller and his “un-American” activities, coupled with a request she made to visit the Soviet Union in 1955. (She never actually made the trip.) If you’re so inclined, you can peruse the file online.

13. Marilyn Monroe's house was bugged.

The only house Monroe ever owned, a modest hacienda in Brentwood, California, was purchased by married actors Michael Irving and Veronica Hamel in the early 1970s, roughly a decade after Marilyn had died there. During a remodel, the couple discovered a sophisticated, government-grade phone tapping system that extended throughout the house.

14. According to Shelley Winters, Marilyn Monroe wasn't much of a cook.

Winters says she once asked the actress to wash lettuce so they could have salad for dinner. When she walked into the kitchen, Winters found Monroe washing each individual lettuce leaf “with a Brillo pad.”

15. But Marilyn Monroe eventually found her footing in the kitchen.

Marilyn Monroe circa 1954.
Marilyn Monroe circa 1954.
Baron/Getty Images

Several of Monroe's recipes were discovered after her death, and in 2010, The New York Times tried making her stuffing recipe for Thanksgiving. They found it surprisingly complex and theorized that “she not only cooked, but cooked confidently and with flair.”

16. Marilyn Monroe was well-read.

Monroe's bookshelf was exceedingly impressive. At the time of her death, she owned more than 400 volumes, including several first editions. Of the thousands of photographs taken of her, she was especially fond of ones that showed her reading. When a director once found her reading R.M. Rilke's Letters to a Young Poet, he asked her how she chose it. "[On] nights when I've got nothing else to do I go to the Pickwick bookstore on Hollywood Boulevard," she told him. "And I just open books at random—or when I come to a page or a paragraph I like, I buy that book. So last night I bought this one. Is that wrong?"

17. Marilyn Monroe helped Ella Fitzgerald book the Mocambo Club.

The rumor has long circulated that Ella Fitzgerald was originally denied due to her race, but according to one biographer, race wasn't the deterrent for nightclub owner Charlie Morrison; Eartha Kitt and Dorothy Dandridge had already played there. The problem was that Morrison didn't believe Fitzgerald was glamorous enough for his patrons. A huge Fitzgerald fan, Monroe promised to be in the front row every night if Morrison would book her, guaranteeing massive amounts of press for the club. He agreed, and Monroe was true to her word. "After that, I never had to play a small jazz club again," Fitzgerald said. "She was an unusual woman—a little ahead of her times. And she didn't know it."

18. Marilyn Monroe had a hard time memorizing lines.

"The joke was, she couldn't make two sentences meet," said Don Murray, an actor who co-starred with Monroe in the 1956 film Bus Stop. Though some chalked it up to a lack of professionalism, others—including Murray—believed it was nerves.

19. Marilyn Monroe's wardrobe is worth a fortune.

Marilyn Monroe's famous "Happy Birthday" dress.
DAN CALLISTER Online USA, Inc./Hulton Archive

At $1,267,500, the sheer, spangled dress Monroe wore to sing "Happy Birthday" to JFK in 1962 set the world record for the most expensive piece of clothing ever sold. A collectible company purchased it. The famous Seven Year Itch dress set a record, too, selling for $4.6 million in 2011. Casual attire goes for less, but still fetches more than your average pair of Levi's: Tommy Hilfiger bought her jeans from Otto Preminger's River of No Return for $37,000—and gave them to Britney Spears as a gift.

20. Frank Sinatra gifted Marilyn Monroe with a dog named Maf.

The Maltese Terrier was a gift from Frank Sinatra, and the dog's full name was “Mafia Honey,” which was apparently a nod to Sinatra’s supposed criminal ties. After Monroe's death, Maf was taken in by Sinatra’s secretary, Gloria Lovell.

21. Maf the dog “wrote” a book in 2010.

In 2010, author Andrew O’Hagan wrote The Life and Opinions of Maf the Dog, and of his Friend Marilyn Monroe—a work of fiction written from Maf’s perspective.

22. Joe DiMaggio and Frank Sinatra once attempted to catch Marilyn Monroe cheating with another man.

In 1954, Joltin’ Joe and Ol’ Blue Eyes were having dinner together when a private investigator that DiMaggio had hired tipped them off that Marilyn was with another man—right that second—in a house not far away. They assembled a crowd—yes, a crowd—and broke into the house where she was allegedly having her tryst.

It wasn’t until they broke the lock on the door and stormed inside snapping photos that they realized it was the wrong house entirely. The whole thing blew up when the homeowner sued; Sinatra had to testify before the California State Senate two years later. The homeowner, secretary Florence Kotz, was awarded $7,500 for her trauma.

23. Marilyn Monroe and Joe DiMaggio were only married for 8 months.

Marilyn Monroe stars in The Seven Year Itch (1955).
Marilyn Monroe stars in The Seven Year Itch (1955).
20th Century Fox Home Entertainment

Their romance is infamous, but Monroe was only married to second husband Joe DiMaggio for a mere 274 days. Though many things contributed to their divorce, the infamous "subway scene" in The Seven Year Itch—where the skirt of Marilyn's white dress billows up—was said to have been the last straw. The scene was shot in front of a large crowd of media and bystanders, and DiMaggio became irate over how much she was exposing herself. They fought over it, and according to some reports, DiMaggio got physical.

24. Marilyn Monroe divorced Joe DiMaggio over "mental cruelty."

Whether or not DiMaggio did get physical with Monroe, their marriage came to an end shortly after The Seven Year Itch incident. Monroe filed for divorce on the grounds of "mental cruelty" not long after.

The kicker? That particular fight was completely unnecessary. The crowd made enough noise that the footage shot that day was completely unusable, so Monroe had to re-shoot her scenes on a closed sound stage.

25. Joe DiMaggio remained devoted to Marilyn Monroe, even after their divorce.

DiMaggio continued to be there when Monroe needed him, including bringing her to spring training with him so that she could get away from Hollywood for a while. Shortly before her death, DiMaggio had been telling friends that they were going to get remarried. When she died, he was in charge of the funeral, and he refused to allow almost anyone from Hollywood to attend. "Tell them, if it wasn't for them, she'd still be here," he said. He had roses delivered to her grave twice a week for 20 years following her death.

26. Marilyn Monroe had been in discussions to star in a biopic about Jean Harlow, one of her heroes, for years.

Marilyn and her friend Sidney Skolsky had long been hatching plans for a biopic of Jean Harlow, which Marilyn would star in and Skolsky would produce. Harlow, another blonde bombshell and Hollywood starlet who died young, was one of Marilyn’s idols—so the self-casting would have been poetic.

27. Even in death, Marilyn Monroe and Jean Harlow had a lot in common.

About DiMaggio having roses delivered to Monroe’s grave several times a week for 20 years following her death? The tradition was taken from Jean Harlow’s untimely death: When she died, fiance William Powell had flowers delivered to her grave every week for years. One account says that Monroe actually asked DiMaggio to deliver on this same morbid promise on their wedding day.

28. Warren Beatty was one of the last people to see Marilyn Monroe alive.

A 25-year-old Warren Beatty was attending a party at actor (and JFK’s brother-in-law) Peter Lawford’s house when he met Monroe for the first time. She asked him to take a walk along the beach with her; he later recalled that “It was more soulful than romantic.” Her death was announced the next day.

29. Marilyn Monroe’s estate earned much more money following Monroe’s passing.

At the height of her career, Marilyn had a million-dollar contract for two films. During the same time frame, Elizabeth Taylor was paid $1 million for her role in Cleopatra alone. It’s estimated that Marilyn was worth about $20 million at the time of her death, which is nothing to sneeze at—but these days, her estate is making $30 million a year.

30. being buried near Marilyn Monroe is a big deal.

Marilyn Monroe's gravesite.
Mel Bouzad/Getty Images

After her death, Monroe was buried at Westwood Village Memorial Park Cemetery in Los Angeles. DiMaggio originally owned the crypt above hers, but sold it when they divorced. The buyer was Richard Poncher, a fan who requested that he be flipped over when he was buried so he could lay face down on top of Monroe for eternity. Charming. Though his wife obliged the request, she changed her mind in 2009 and put the plot up for sale on eBay. It brought in a whopping $4.6 million, but the buyer later backed out.

Hugh Hefner famously purchased the plot right next to hers. Though she graced the first cover of Playboy, the two never met. "I feel a double connection to her because she was the launching key to the beginning of Playboy," he said. When Hefner died in 2017, he was buried in the plot he'd bought for $75,000 in 1992.

This story was updated in 2020.

10 Products for a Better Night's Sleep

Amazon/Comfort Spaces
Amazon/Comfort Spaces

Getting a full eight hours of sleep can be tough these days. If you’re having trouble catching enough Zzzs, consider giving these highly rated and recommended products a try.

1. Everlasting Comfort Pure Memory Foam Knee Pillow; $25

Everlasting Comfort Knee Pillow
Everlasting Comfort/Amazon

For side sleepers, keeping the spine, hips, and legs aligned is key to a good night’s rest—and a pain-free morning after. Everlasting Comfort’s memory foam knee pillow is ergonomically designed to fit between the knees or thighs to ensure proper alignment. One simple but game-changing feature is the removable strap, which you can fasten around one leg; this keeps the pillow in place even as you roll at night, meaning you don’t have to wake up to adjust it (or pick it up from your floor). Reviewers call the pillow “life-changing” and “the best knee pillow I’ve found.” Plus, it comes with two pairs of ear plugs.

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2. Letsfit White Noise Machine; $21

Letsfit White Noise Machine
Letsfit/Amazon

White noise machines: They’re not just for babies! This Letsfit model—which is rated 4.7 out of five with nearly 3500 reviews—has 14 potential sleep soundtracks, including three white noise tracks, to better block out everything from sirens to birds that chirp enthusiastically at dawn (although there’s also a birds track, if that’s your thing). It also has a timer function and a night light.

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3. ECLIPSE Blackout Curtains; $16

Eclipse Black Out Curtains
Eclipse/Amazon

According to the National Sleep Foundation, too much light in a room when you’re trying to snooze is a recipe for sleep disaster. These understated polyester curtains from ECLIPSE block 99 percent of light and reduce noise—plus, they’ll help you save on energy costs. "Our neighbor leaves their backyard light on all night with what I can only guess is the same kind of bulb they use on a train headlight. It shines across their yard, through ours, straight at our bedroom window," one Amazon reviewer who purchased the curtains in black wrote. "These drapes block the light completely."

Buy it: Amazon

4. JALL Wake Up Light Sunrise Alarm Clock; $38

JALL Wake Up Light Sunrise Alarm Clock
JALL/Amazon

Being jarred awake by a blaring alarm clock can set the wrong mood for the rest of your day. Wake up in a more pleasant way with this clock, which gradually lights up between 10 percent and 100 percent in the 30 minutes before your alarm. You can choose between seven different colors and several natural sounds as well as a regular alarm beep, but why would you ever use that? “Since getting this clock my sleep has been much better,” one reviewer reported. “I wake up not feeling tired but refreshed.”

Buy it: Amazon

5. Philips SmartSleep Wake-Up Light; $200

Philips SmartSleep Wake-Up Light
Philips/Amazon

If you’re looking for an alarm clock with even more features, Philips’s SmartSleep Wake-Up Light is smartphone-enabled and equipped with an AmbiTrack sensor, which tracks things like bedroom temperature, humidity, and light levels, then gives recommendations for how you can get a better night’s rest.

Buy it: Amazon

6. Slumber Cloud Stratus Sheet Set; $159

Stratus sheets from Slumber Cloud.
Slumber Cloud

Being too hot or too cold can kill a good night’s sleep. The Good Housekeeping Institute rated these sheets—which are made with Outlast fibers engineered by NASA—as 2020’s best temperature-regulating sheets.

Buy it: SlumberCloud

7. Comfort Space Coolmax Sheet Set; $29-$40

Comfort Spaces Coolmax Sheets
Comfort Spaces/Amazon

If $159 sheets are out of your price range, the GHI recommends these sheets from Comfort Spaces, which are made with moisture-wicking Coolmax microfiber. Depending on the size you need, they range in price from $29 to $40.

Buy it: Amazon

8. Coop Home Goods Eden Memory Foam Pillow; $80

Coop Eden Pillow
Coop Home Goods/Amazon

This pillow—which has a 4.5-star rating on Amazon—is filled with memory foam scraps and microfiber, and comes with an extra half-pound of fill so you can add, or subtract, the amount in the pillow for ultimate comfort. As a bonus, the pillows are hypoallergenic, mite-resistant, and washable.

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9. Baloo Weighted Blanket; $149-$169

Baloo Weighted Blanket
Baloo/Amazon

Though the science is still out on weighted blankets, some people swear by them. Wirecutter named this Baloo blanket the best, not in small part because, unlike many weighted blankets, it’s machine-washable and -dryable. It’s currently available in 12-pound ($149) twin size and 20-pound ($169) queen size. It’s rated 4.7 out of five stars on Amazon, with one reviewer reporting that “when it's spread out over you it just feels like a comfy, snuggly hug for your whole body … I've found it super relaxing for falling asleep the last few nights, and it looks nice on the end of the bed, too.” 

Buy it: Amazon 

10. Philips Smartsleep Snoring Relief Band; $200

Philips SmartSleep Snoring Relief Band
Philips/Amazon

Few things can disturb your slumber—and that of the ones you love—like loudly sawing logs. Philips’s Smartsleep Snoring Relief Band is designed for people who snore when they’re sleeping on their backs, and according to the company, 86 percent of people who used the band reported reduced snoring after a month. The device wraps around the torso and is equipped with a sensor that delivers vibrations if it detects you moving to sleep on your back; those vibrations stop when you roll onto your side. The next day, you can see how many hours you spent in bed, how many of those hours you spent on your back, and your response rate to the vibrations. The sensor has an algorithm that notes your response rate and tweaks the intensity of vibrations based on that. “This device works exactly as advertised,” one Amazon reviewer wrote. “I’d say it’s perfect.”

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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.

Argentine ants
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.