Researchers at the University of Texas are warning that an invasive species from South America has the potential to change the ecological balance in the southeastern United States by wiping out one of the region's other pests, fire ants, USA Today reported.

The crazy ants, an ecologically dominant species native to Argentina and Brazil, are becoming a nuisance along the U.S. Gulf Coast. On Oct. 26, Reuters reported that "legions" of the tiny ants have been marching through several homes in Texas, Louisiana, Mississippi, Georgia and Florida.

"Perhaps the biggest deal is the displacement of the fire ant, which is the 300-pound gorilla in Texas ecosystems these days," Ed LeBrun, a research associate with the Texas Invasive Species Research Program at the Brackenridge Field Laboratory in the College of Natural Science, said in a statement. "The whole system has changed around fire ants. Things that can't tolerate fire ants are gone. Many that can have flourished.

"New things have come in. Now we are going to go through and whack the fire ants and put something in its place that has a very different biology. There are going to be a lot of changes that come from that," he said.

These ants are omnivores that can take over an area by both killing what's there and starving out what they don't kill, LeBrun said.

As a result, the crazy ants are reducing diversity and abundance across a range of ant and arthropod species - but their spread can be limited if people are careful not to transport them inadvertently.

According to the report, the crazy ants don't sting nor do they bite -- but they do reproduce at rapid speeds. They like to make their home in warm, tight spaces including around electrical equipment, under floorboards and in car engines, areas where they can do massive damage.

But now officials are concerned about the fate of the fire ant.

"When you talk to folks who live in the invaded areas, they tell you they want their fire ants back," LeBrun said. "Fire ants are in many ways very polite. They live in your yard. They form mounds and stay there, and they only interact with you if you step on their mound."

LeBrun said the crazy ants, by contrast, "go everywhere." They invade people's homes, nest in crawl spaces and walls, become incredibly abundant and damage electrical equipment.

According to Reuters, although financial losses have not officially been recorded, Tom Rasberry, a Houston exterminator credited by local experts with discovering the ants in the U.S., believes the costs over a decade of damage could be in the hundreds of millions.

According to researchers, the poco loco ants were first discovered in the U.S. in 2002 by a pest control operator in a suburb of Houston, and have since established populations in 21 counties in Texas, 20 counties in Florida, and a few sites in southern Mississippi and southern Louisiana.