http://news.nationalgeographic.com/news/2009/01/090121-lizard-ants-missions.html
"The venom-packed stings of just 12 fire ants can kill a three-inch-long (eight-centimeter-long) fence lizard in a minute, according to lead study author Tracy Langkilde, a biologist at Pennsylvania State University. The ants have been known to strip animals as large as calves down to the bone.
But some lizards twitch vigorously and flee the scene whenever ants attack, a defensive behavior that sheds the insects before they can pry up the reptiles' scales and sting the soft flesh underneath."
"Fire ants were accidentally introduced to the U.S. from South America in the 1930s, possibly via shipping ports in Alabama.
Without a method for controlling the population, scientists believe fire ants—which have no natural predators, in the U.S.—will eventually colonize more than 50 percent of Earth's land surface."
"Duncan Irschick is a biologist at the University of Massachusetts in Amherst who uses lizards as a model to study evolution. He said Langkilde's research presents solid evidence that these are evolved traits.
What's more, the findings highlight the ability of organisms to adjust to environmental changes beyond their control, he added.
"It says there is some hope for species, that they can rapidly evolve to meet new challenges," Irschick said."