Cordyceps Fungus Eliminates a Carpenter Ant Colony

The elimination of a carpenter-ant colony by a Cordyceps-related fungus became both a practical demonstration of Paul Stamets’s ingenuity and the source of the patent proceeds that helped build his later home. The episode turns the struggle between ants and fungus into a precise contest of timing: the ants’ defenses depended on recognizing the threat, while Stamets’s solution let the fungus enter the colony before revealing itself.

The Infestation and the Ants’ Defense

When Stamets moved into the old farmhouse, it was being slowly damaged by carpenter ants. He knew that a species of Cordyceps could destroy the colony, but the ants had a defense of their own: they inspected returning members for Cordyceps spores and removed those carrying them. A fungus that began releasing spores too soon would be detected before it could spread through the nest.

A Delayed Attack

Stamets bred a mutant Cordyceps-like fungus that postponed sporulation. He placed some of its mycelium in a bowl in his daughter’s dollhouse and left it on the kitchen floor. During the night, ants carried the material into their nest, treating it as a safe food source. By the time the fungus sporulated, it was established inside the colony; it colonized the ants and the infestation was eliminated.

From Patent to House

The farmhouse could not be saved. Stamets’s sale of the fungus patent, however, provided the proceeds to build the more imposing house that later stood on the site. The episode therefore links a small domestic problem to the larger work of mycological invention: the house was not merely a setting for Stamets’s research, but, as his account framed it, a consequence of that research. The decisive advantage came from working around the ants’ detection system rather than confronting it directly.