That seems to have led more omnivores to abandon meat, says Roberto Moyano, the manager of La Esquina de las Flores, the capital's oldest vegetarian restaurant.

ECONOMIST: Argentina's meaty diet

The crazy ants, officially called "Tawny crazy ants, " are omnivores that can take over an area by both killing what's there and starving out what they don't kill, said Ed LeBrun, a research associate with the Texas invasive species research program at the Brackenridge Field Laboratory in the College of Natural Sciences.

CNN: 'Crazy ants' a threat in southern U.S.