A new study shows that tawny crazy ants — also known as Nylanderia fulva in Latin — use secretions of formic acid to detoxify wounds sustained in battles with venomous fire ants. The crazy ants, currently sweeping across the southern United States, secrete the acid from their abdominal glands. Scientists believe the behavior likely evolved in the two species' native region of South America, and that the competitive advantage it provides is the reason that crazy ants are gradually displacing fire ants in the States.

Conducted by the Brackenridge Field Laboratory at the University of Texas at Austin, the research finds that "N. fulva captured 93 percent of contested resources" and even invaded and usurped fire ant mounds. Evidently, being able to recover from their direct competitor's most lethal weapon is helping the crazy ants win the battle for supremacy.

Better than antacids

To test their hypothesis, the scientists staged "antagonistic interactions" between the two species and observed that, after being hit with the fire ant's poison, the crazy ant worker "grooms itself vigorously" with its own acid secretions. While the use of such defensive compounds is apparently "widespread and amazingly varied" among ants, the unique aspect to the crazy ants' behavior is the self-application of an antidote to a specific competitor's venom.