Deadly takeover: Imposter ant queen tricks loyal workers into murdering their mother, seizes the throne

The parasitic Lasius orientalis queen (left) enters a Lasius flavus nest and moves toward the resident queen (right) to release her chemical spray. (Image: Keizo Takasuka/Kyushu University)

Deep inside a quiet soil nest, something unsettling unfolded. Workers rushed in circles as a strange scent filled the air. A visiting queen had started a battle that no ant expected.

How do invading queens seize control?

Researchers found that parasitic queens used bold deception. They entered nests belonging to other ant species. They then sprayed the host queen with sharp formic acid. This erased her scent and confused the loyal workers badly. The workers reacted with fear and attacked their own mother. The findings came from a study published in Current Biology. The work was led by biologist Keizo Takasuka in Japan. He spoke about the results to Live Science in an email.

Why does the colony kill its own queen?

Ant workers rely strongly on scent for recognition. Their nests stay dark and vision stays limited always. Parasitic queens first copy the colony scent through grooming. This scent theft gives them near-perfect invisibility. After gaining acceptance, they approach the host queen closely. The invader sprays her with acidic fluid instantly. The workers detect danger and launch violent attacks. If the host queen survives, the invader repeats the spray. Eventually the mother queen dies under worker attacks.

How do invading queens blend into the colony?

After the host queen dies, the parasite waits quietly. The workers settle down and resume normal care. The invader begins laying eggs inside the nest. Workers then raise the brood as they usually do. As old workers die out, her scent becomes dominant. She no longer needs to copy scents every day. Experts say she blends smoothly into colony life. Daniel Kronauer at Rockefeller University supported these ideas. He explained how workers rely fully on odour signals.

Why is this behaviour unusual in nature?

Some insects show natural patterns of maternal sacrifice. Earwig mothers may offer their bodies as food. Wasps sometimes kill queens for colony diversity gains. But these ant events favour only the parasite queen. The resident workers gain nothing and lose everything. Kronauer called the behaviour selfish from the parasite’s view. He added the worker response was non-adaptive behaviour entirely.