Bird nests made with a toxic fungus seem to fend off attacking ants
So Cortés-Romay and behavioral ecologist Sabrina Amador Vargas of the Smithsonian Tropical Research Institute in Balboa, Panama, placed strands of horsehair fungus onto the branches of 30 acacia trees inhabited by one species of symbiotic ant (Pseudomyrmex spinicola), along with fibers of a nonfungal plant of similar thickness and type that birds also use to build nests.