Red Imported Fire ants (Solenopsis invicta) have been present in North America since the 1930s, having been accidentally transported from South America through the shipping industry to the southeastern United States. Certainly they are a nuisance to humans, but their negative impacts on our natural ecosystems have been extensive. They are aggressive and have overtaken and displaced many native ant species. Though they may fill the same role as a decomposer, or "clean up" insect, they do not fill the role of prey for all the animals that consume native ants, thus disrupting the web of life. These fire ants are also capable of taking live prey. As a result, anything in their path on the ground or in the trees is a potential source of food. Many in Central Texas are familiar with stories of newly born fawns or calves on the ground being overtaken and killed by a swarm. What many may not realize is these ants have been documented consuming young golden-cheeked warblers in a nest between 10 and 20 feet off the ground. They will also venture into caves where protected species live, potentially consuming those animals or consuming the food those obligate cave species require.

On the Balcones Canyonlands Preserve, management of these fire ants occurs around the entrances to caves known to contain protected species. Treatment of mounds with boiling water occurs several times a year on days with specific weather conditions-cloudy days that are mild and dry. On these days, fire ants will move the queen higher up in their mound and fairly close to or at ground level. Chemicals are never used because of their potential to kill protected species, alter the health of the cave ecosystem, and negatively impact water quality. Staff transports a special tank to a site that heats water to boiling and uses a hose or carries pots of hot water to treat the mounds. Homeowners should be sure they are dealing with the red imported fire ant and not a native ant species before pursuing a form of treatment.

Locally, the University of Texas has become very active in managing these imported fire ants with the introduction of a specific species of phorid fly. Phorid flies as a group are predatory on many species of fire ants, many being very specific to a particular species. To learn more about their research efforts, visit the University's Brackenridge Field Laboratory website at http://uts.cc.utexas.edu/~gilbert/research/fireants/.