First discovered by a Houston pest exterminator in 2002, the Tawny Crazy Ant is the latest insect invader from South America.
"We don't have a precise idea of exactly where or when it arrived," Edward LeBrun, a researcher with the University of Texas, said. "The overall impression when you're looking at a large group of ants is that they're all kind of running around like crazy."
Now found in Florida, Mississippi, Louisiana and 21 Texas counties, LeBrun says crazy ants don't sting, but they are prolific breeders, overrunning all the other ants and insects
"Very large colonies with many, many queens in them,” LeBrun said. “So they have the potential to grow very, very rapidly."
The bad news is that tawny crazy ants like to nest in buildings and structures, often damaging electrical equipment.
"Imported fire ants build a mound in your yard and stay there, unless you happen to step on their colony,” the U.T. researcher said. “These guys come in, they nest in the walls and the crawl spaces. They forage inside your house and they can reach really, really large numbers."
Commonly-used bait pesticides aren't very effective and when crazy ants show up, red fire ants are pushed out.
"It's unclear if that's stable or with a lot more time the imported fire ant will just disappear altogether," LeBrun said.
Much is still unknown about the Tawny Crazy Ant and how it will affect the ecosystem. The Texas climate may help limit their spread.
"I don't think they're well-adapted to cold winters here and that's going to be part of what restricts their ultimate range," the researcher said.
Since Tawny Crazy Ants can't fly, the only way they spread over long distances is when humans move them. They're often found in garbage, compost, potted plants and hay bales in infested areas.