Crazy Ants Use Formic Acid To Wash Off Fire-Ant Venom; Becoming Dominant Invasive Species In US Southeast

Wood ants spray formic acid from their abdomens as a defense. The acid gives off a pungent odor, but does't hurt unless it gets into an open wound, which is most often caused by the ants biting with their powerful jaws. The acid fumes also irritate the nose and mouth causing coughing and choking. | Wild About Nature