By Jeff Devine, Editor-in-Chief, Dale County Chronicle
In this week’s edition of Chronicle Science Review, we explore the bizarre world of a species of ants that behaves in ways never before seen in myrmecology, the branch of entomology that focuses on studying ants. Buckle up—because this is an interesting and slightly terrifying look at ants that use chemical warfare to overthrow queens and replace them with a parasitic monarch.
Scientists say they’ve uncovered, for the first time, the secret behind how a parasitic ant queen mounts a hostile takeover—using chemical deception to trick worker ants into killing their own ruler.
The bizarre operation plays out like an insect-sized Shakespearean tragedy. Inside the colony, the resident queen finds herself under attack by her own daughters. Watching from the shadows is the true mastermind: an invading queen from a different species, armed with chemical weaponry brewed within her body. Her goal is simple—slip into the nest unnoticed and manipulate loyal subjects into assassinating the rightful monarch.
While ants sometimes turn on their own queen due to aging or competition between multiple queens, researchers say this is the first time anyone has documented an outsider manipulating workers into performing the killing for her. The findings were published this week in the journal Current Biology (Volume 35, Issue 22, Pages 5392-5668).
Dr. Keizo Takasuka of Kyushu University, the study’s senior author, said such induced matricide had never been observed in the animal kingdom. His team studied ants in the Lasius genus, focusing on infiltrations carried out by L. orientalis and L. umbratus queens.
Earlier research showed that a parasitic queen could disguise herself by grabbing a worker from a host colony and rubbing it across her body, masking her scent. But the mechanism behind worker-initiated queen killings had remained a mystery—until now.
To crack the case, two Tokyo-based citizen scientists each raised ant colonies and introduced invading queens. Before entering the nests, each parasitic queen was co-housed with host workers and cocoons so she could adopt their scent and pass as a nestmate. Once she blended in, the intruder made her move.
At first, the workers barely reacted to the unfamiliar queen—some even shared food with her. But her mission wasn’t socializing. After locating the resident queen, the invader blasted her with abdominal fluid likely laced with formic-acid-like chemicals. The irritated workers reacted instantly, attacking their own queen. With each chemical spray, the aggression escalated.
The Dale County Chronicle reached out to experts on ants at Auburn University (Auburn) and Auburn University Montgomery (AUM) for additional information on this phenomenon. Auburn entomologist Dr. Clint Penick said the findings reveal just how complex and vulnerable ant societies can be when communication is disrupted.
“Ant societies are incredibly sophisticated, so it is fascinating how a parasite can hijack their communication system to make the workers do the one thing they’re not supposed to—kill their own queen,” Penick said.
Within four days, the workers had killed their true mother. Once the throne was empty, the parasitic queen immediately began laying hundreds of eggs, cared for by her newly converted “daughters.” Eventually, her own offspring would dominate the colony entirely, wiping out the original species from within.
AUM entomologist Dr. Denise Stoeckel remarked upon the vicious nature of this species, saying, “How vicious are these little creatures who do not have a full formed brain. Insects have two ganglia (a ball of neurons) that control all of their neurological functions. It amazes me that so much complicated behavior is displayed by organisms that have a “brain” we consider underdeveloped.”
Stoeckel also remarked upon the fact that the worker ants do not attack the invading queen. “How does this parasitic queen not attract an attack on herself? There is evidence…where workers are sniffing the abdomen of the parasitic queen. They do not attack her but attack their own queen that was sprayed,” she added. Stoeckel added she would be interested in seeing an analytical study conducted on the chemical used by the parasitic ant queen. She pointed out it would be interesting to see if the chemical could be extracted and used as a natural, nontoxic mechanism to “control nuisance species that we have here, like fire ants. I’m sure there are other very useful methods that could come out of the continuing study of this phenomenon,” she said.
Penick also noted there is still much scientists don’t understand about the chemical mechanisms at play.
“This study raises a lot of interesting questions about how this behavior has evolved, and especially what chemical compounds induce the workers to attack,” he said. “While the authors speculate that it might be formic acid, I would guess that there might be more to it than that.”
He also pointed out that despite the chaos, the workers never turned on each other.
“If there was a simple chemical signal that told workers to ‘attack,’ then you might expect it to trigger a similar response towards workers who caught any overspray,” Penick said. “The lack of worker-on-worker fighting suggests that the chemical signal must interact with the queen’s own scent to trigger the response somehow.”
That raises one more mystery—even more impressive, perhaps, than the parasitic queen’s ability to manipulate the colony.
“I was also wondering how the parasite queen avoids leaving any kind of residue on herself that might cause workers to attack her instead,” Penick added. “She must deliver a really clean shot!”
Social parasites like these ants target colonies rich in shared resources. Some species enslave kidnapped brood, while others—like the queens in this study—simply replace the ruling monarch and take over.
Folklore is filled with dark stories of family betrayal, but scholars note that tales involving children being tricked into killing a parent are nearly unheard of. That’s part of what makes these ant invasions so remarkable.
“Sometimes nature outdoes fiction,” Takasuka said—proving that even the tiniest creatures can stage the most dramatic coups.
