This species invades other colonies by making the community kill their ‘mother’

When Shimada introduced the impostor queen at the entrance of a real Lasius flavus nest, she acted as if she ruled there. Workers fed her, and those who challenged her were brushed away. Hours later, the invader found the resident queen, the colony’s mother.

The coup began. The parasitic queen sprayed the resident queen with a fluid—likely formic acid—that altered her scent. This caused confusion and agitation among the workers, who suddenly no longer recognised their mother. They began attacking her.

Over four days, the invader sprayed the resident queen 15 times. Disturbed by this chemical signal, workers tore apart their own queen. Afterwards, they accepted the parasitic queen as their ruler. Within ten days, she began laying eggs, and within a year, the entire colony—about 3,000 ants—consisted only of her offspring.

This discovery emerged thanks to hobbyist observations, later validated scientifically by ecologist Keizo Takasuka. Similar takeovers by related species suggest this dramatic form of chemical matricide is more common than previously thought.

Researchers note this behaviour is unique because the killers gain nothing—the benefit goes entirely to the invading queen. It reveals how much remains unknown about the complex social behaviours of ants, even in species that surround us daily.

Even the smallest ant colonies wage silent, deadly battles beneath our feet. Chemical warfare and cunning deception govern their secret wars. This research sheds new light on parasitic strategies in social insects and the evolutionary arms race played out in ant colonies worldwide.