There's a new player on the continent and it is spreading damage from Texas to Florida in a scary assault that sounds like a really bad movie.
"Crazy" ants on the march have a taste for everything from livestock to electrical equipment. They are so obnoxious that many residents yearn for the good old days when all they had to fight was red ants that are quickly being wiped out by the crazies.
The tiny insect is called "crazy" because the trail it leaves as it eats its way across the country is so erratic it appears the ants have tipped the bottle too many times.
Scientists know it as Nylanderia fulva, but its commonly accepted name is "tawny crazy ant," formerly known as the raspberry crazy ant.
By whatever name, it's here now, transported from its homeland in Argentina and Brazil, probably unwittingly, by humans. It's so small -- less than an eighth of an inch long -- that millions can hide beneath a rock, or inside a computer or transformer.
The newcomer was first sighted near Houston in 2002, but they have since moved on to 21 counties in Texas, 20 counties in Florida, and a few sites in Mississippi and Louisiana, all with human assistance.
It doesn't sting, but it has an annoying bite that can scare wildlife away -- and, unlike its more famous cousin, the red ant, it is highly invasive, infesting homes, recreational vehicles, transformers and any laptop or smart phone left in its path.
Crazy ants, according to researcher Ed LeBrun of the University of Texas, Austin, just simply aren't very polite. LeBrun is co-author of a study on crazy ants published in the journal Biological Invasions.
LeBrun and his colleagues have found that the omnivorous ants attack and kill other species and monopolize food resources so efficiently that they jeopardize the entire ecosystem.
They are near the bottom of the food chain, but they could have a devastating effect on plants and animals ranging from cattle to songbirds.
According to researchers at Texas A&M, the chemicals that kill red ants aren't effective on crazy ants, so if you find an infestation in your home, call a pro.
Both reds and crazies and a few other species share a peculiar attraction to electrical wiring and components, and no one is sure why. The damages can be extreme. In one year alone, researchers documented $146.5 million in damages to electrical equipment just in Texas.
How they cause that damage also sounds like a really bad movie. One ant finds its way into a transformer and grazes against a hot wire. It gets electrocuted, and immediately "waves its abdomen in the air (called gaster flagging) to release its own brand of perfume, which lures many more ants to the scene.
If they touch their fallen comrade, or a hot switch, they too will be electrocuted, sending more pheromones into the air and calling even more ants to their location.
Pretty soon, there are so many dead ants that the electric switches can't close, or the insulation is fried and the system short circuits.
Ants have been found to remove enough soil from beneath a slab to cause the slab to tilt, and the damage doesn't end there. They can carry the soil to the warm interior of a transformer, where it collects moisture and eventually shuts down the electronics.
Another species, called acrobat ants, infiltrated an air conditioner in Austin, Texas, causing it to malfunction and costing the homeowner $196.54.
"Perhaps the biggest deal is the displacement of the fire ant," LeBrun said, in releasing his study. "The whole ecosystem 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."
LeBrun found that in two areas studied by his team, red ants were completely eliminated when crazy ants by the millions moved in. Either the red ants moved on, or they died because of competition for resources. A lot is still unknown about what exactly is causing what in this ongoing competition.
What is clear, however, is the role humans have played in the introduction of this new warrior. Crazy ants do not travel great distances on their own. The only way they could have arrived in North America and spread across several states is with human help.
So LeBrun urges people traveling in those areas where the ants are showing up, and especially to the crazy ant's homeland in South America, to check their luggage carefully for any sign of the critters. It doesn't require a lot of space for an entire colony to set up shop, and they propagate at an amazing rate.
The researchers found that crazy ant colonies reached densities 100 times greater than all the other ants in their area combined. It doesn't take many to make a huge impact.
So maybe it's not as crazy as it sounds.