The mystery of ‘zombie ants': How a mind-controlling fungus hijacks nature

Indian Express

4 days ago

A fascinating and eerily sophisticated biological puppet show unfolds deep in tropical forests worldwide. The star is Ophiocordyceps unilateralis, a parasitic fungus that transforms carpenter ants into 'zombies,' manipulating them with remarkable precision to ensure its survival.
The process begins when an unsuspecting ant encounters a fungal spore. The spore penetrates the ant's protective exoskeleton using a combination of enzymes and pressure. Once inside, the fungus begins its insidious takeover, spreading throughout the ant's body while carefully avoiding its brain.
What happens next is both fascinating and disturbing. The infected ant abandons its normal behaviour and colony responsibilities, entering what scientists call the 'zombie phase.' As reported by The Atlantic, the fungus compels the ant to climb 'exactly 25 centimeters above the forest floor, no more and no less' — a height that provides optimal conditions for fungal growth. The ant then clamps its jaws onto a leaf vein in a death grip, where it remains until its final moments.
The fungus's manipulation of its host is extraordinarily precise despite its lack of a brain or nervous system. Recent research has revealed surprising insights into how this control is achieved. According to the Library of Congress, researchers discovered that rather than attacking the brain directly, the fungus appears to control the ant's muscles. The fungus grows around the brain while infiltrating every other part of the ant's body, suggesting a sophisticated method of behavioural control that scientists are still working to understand.
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The Atlantic reports an even more remarkable finding: the fungal cells work cooperatively, forming a complex network within the ant's body. As Pennsylvania State University entomologist David Hughes's research revealed, the fungal cells connect through specialised tubes, allowing them to 'communicate and exchange nutrients.' This network essentially turns the fungus into a colonial organism, much like the ants it parasitises.
The grand finale of this biological horror show occurs when a fungal stalk erupts from the dead ant's head, releasing spores onto unsuspecting ants below. This strategic positioning ensures the cycle continues, as the spores rain down on foraging trails used by the ant's former nestmates.
Despite its terrifying efficiency in controlling ants, O. unilateralis faces its own challenges. The Library of Congress notes that this fungus has its own parasites — hyperparasites like Niveomyces coronatus and Torrubiellomyces zombiae that may help keep its lethal effects in check, preventing it from completely decimating ant populations.