First detected near Houston, Texas, in 2002, Nylanderia fulva has now made its way to Georgia.
Called by the owner of an Albany, Ga., assisted-living facility, Morgan County Cooperative Extension Agent James Morgan found thousands of dead ants in the corner of a bathroom in a vacant duplex.
They had come in looking for food, and the ants also seem to go inside to die, he said. Morgan found plenty of live ants outside, in the lawn under debris and in an outbuilding.
Morgan knew these ants were different from the usual ants he sees, such as fire ants or little black Argentine ants – both of which also are exotic invasive species, from northern Argentina and Brazil.
Georgia has between 50 and 60 native ant species, but the crazy ants could displace some of them.
In Texas, ecologists worry that the tawny crazy ant might even doom some native species to extinction.
As part of efforts to keep out such noxious invader, University of Georgia entomologist Dan Suiter is trying to develop a kind of map of ant species in the area around the port of Savannah, one of the East Coast’s busiest ports and a major entryway for invasive species.
“We’re up to 48 species. A whole bunch are not native, but don’t have pest status,” Suiter said. “There’s dozens and dozens of exotic species, but most are in low numbers.”
Inspectors do their best to screen out contaminated loads, but they don’t catch everything.
“They are very diligent, but sometimes things just get through,” he said.
Private boats that go from country to country can unknowingly bring in alien plants and animals, he said.
The new invaders got the “crazy” name because of their jerky, seemingly erratic paths as they forage for food, Suiter said.
Pest control professionals are working at the Albany assisted-living facility to control the millions of crazy ants, Morgan said. They’re not likely to be able to eradicate them. By the time the ants are found, they’ve already built up huge, spreading populations.
“There’s no such thing (as eradication),” Suiter said. “With most invasive species, once you detect them, usually by that point it’s too late.”
Since first being identified in Texas in 2002, they’ve since been found in Mississippi, Florida and Louisiana. Entomologists expect someone will find them in Alabama any day now.
Their march through Georgia might not take them to Athens; it may be too cold for tawny crazy ants, Suiter said.
Another less bothersome species, the black crazy ant, is found as far north as Savannah, he said.
The ants’ distribution across the Southeast is spotty for now. Suiter suspects someone may have inadvertently brought them to Albany from Texas or another Southern place already infested, perhaps in a nursery’s potted plant.
“We’ll never know,” he said.
Morgan didn’t know he was looking at a new Georgia ant species when he went to the assisted living facility. But he knew he hadn’t seen anything like them.
“Once we found them outside, they were just running around a little frantic. Just by their movement they were different. You haven’t seen an ant move as fast as that,” he said.
Tawny crazy ants are small, nearly as small as Argentine ants. And they don’t sting like fire ants, Morgan said.
“They’re fairly calm,” he said.
But they can be a major nuisance for homeowners. The species travels in great swarms, which throw off buds that develop into new colonies. And instead of building nests, the tawny crazy ant likes to take advantage of pre-existing spaces to hang out, such as the insides of electrical boxes.
They’re pretty small, only slightly bigger than Argentine ants, so they can get into tiny cracks. They invade kitchens by the millions.
Suiter didn’t know of any fires started by tawny crazy ants, but when they jam into areas with electric wires, their sheer numbers can cause short circuits, he said.
And tawny crazy ants are hard to control, even with professional help, Suiter said.
Keeping them down to manageable numbers can require frequent professional insecticide treatments. Sealing up tiny cracks where they can enter a house also helps, Suiter said.
Although the new ants don’t sting, they’re in many ways a far worse pest than fire ants, and can actually displace stinging fire ants, according to research by University of Texas ecologist Ed LeBrun.
In the areas of Texas they studied, tawny crazy ants had either eliminated or drastically reduced fire ants, LeBrun and co-researchers wrote in the journal Biological Invasions.
Because they have no natural enemies here, the crazy ants can reach population densities up to 100 times as great as all the other ants in an area combined, according to the Texas researchers.
Fire ants changed the ecology in areas where they invaded; now the tawny crazy ants will wreak new ecological transformations, affecting not just other ants, but the area’s whole web of plant and animal life. They reduce biodiversity at the base of the food chain, they wrote.
“It will have a cascade effect ecologically, like all invasive species do,” Suiter said. “It will probably drive some local ants to extinction.”