These Ants Kill Their Own Queen

Explore

WWho knew that ants were the masters of melodrama? Colonial organisms have long enchanted entomologists and animal behaviorists with their impressive physiological capabilities, unique social structures, and astonishing diversity (there are more than 15,000 named species and subspecies of ants). But now, two species of ants have added a macabre twist to their bag of tricks: they’re killing their own mother.

Before jumping to conclusions, know that they are not doing this on purpose. Matricid ants are chemically coerced into murderous behavior.

As Japanese researchers report in Current biology today, colonies of two species of ants, Lasius flavus And Lasus japonicusare invaded by two distinct species of parasitic ants (Lasius orientalis And Lasius ombratusrespectively) which dispatch queens from host colonies by manipulating host workers into attacking it. The key to influencing the behavior of their victims is to spray a chemical directly onto the host queens. Parasitic ants gain cooperation from their victims by spraying their queen with a chemical that workers associate with danger. Once the invading queens spray the hapless host queens – with what the study authors suggest is formic acid – the host workers dismember and kill them, their own mothers. They then accept the parasitic queen and care for the new eggs she lays once the deceptive act is complete.

“In both cases, the host and the parasite belong to the same genus, so they both contain formic acid and recognize it as a danger signal,” says Kyushu University biologist Keizo Takasuka, co-author of the paper, in a statement. “We think that when their queen is suddenly covered in a large amount of this chemical, the workers perceive their own mother as a colony-threatening crisis that triggers their aggressive defensive behavior.”

Although the research team first formally documented this fascinating interaction between parasite and host colonies, it was avid ant hobbyists who first made them aware of this behavior. Taku Shimada, who runs a popular Japanese-language blog called AntRoom, first discovered the ants’ vile dynamic between L. orientalis And L. flavus and spoke about it in 2021. He is the first author of the journal. Another ant observer, Yuji Tanaka, discovered the interaction between L. umbratus And L. japonicusand is listed as the second author.

Read more: »Do you want to come out alive? Follow the ants»

The feat of manipulating workers into killing their own queens can only be accomplished once the invading colony has overtaken the guards. Invading parasites manage to penetrate these defenses using even more olfactory deceptions. “Direct infiltration would fail because the workers would immediately perceive the intruder and attack it,” Takasuka noted. “To achieve this, the parasitic queen was housed with a few host workers and cocoons. After just one night, she acquired the specific odor of the host colony, providing chemical camouflage that was essential for her to get past initial defenses.”

Maybe it’s a dog eat dog world. But those who keep their eyes glued to the fascinating microcosms that stir beneath our feet know that it is in fact an ant world that encourages other ants to kill their own mother world. I guess that’s kind of a mouthful for an aphorism.

Enjoy Nautilus? Subscribe for free to our newsletter.

Main image: Keizo Takasuka / Kyushu University

• Bob Grant

  Published on November 17, 2025

  Bob Grant is the associate editor of Nautilus.