Even fire ants take a beating when this guy goes cray-cray.

Fire Ants
Credit: Michael Durham/Minden Pictures/Getty Images

Cobras have honey badgers. Great white sharks have killer whales. And now, the despised imported fire ant may have found its own nemesis. It isn't an anteater, a fungus, or even a can of bug spray. It's a smaller ant aptly named the "crazy ant."

Native to Central and South America, the red imported fire ant (Solenopsis invicta) is thought to have entered the United States through the port of Mobile, Alabama sometime in the late 1930s. It quickly spread throughout the South as far north as Maryland and then turned left along the Gulf Coast and made it to southern California. Known for building large mounds of excavated soil that may contain 100,000 workers and single or multiple queens, the red imported fire ant is armed with a sting used to subdue prey and defend the nest against perceived threats.

In too many cases, the perceived threat is you or another person who unwittingly steps on the mound. Thousands of angry workers boil from the ground to sting you. Stings leave painful, itchy pustules. Single stings can cause sensitive people to die from anaphylactic shock. Fire ants also injure and kill livestock, devastate ground-nesting birds, and drive out native ants. Granted, they kill and eat harmful bugs along the way, but the bad far outweighs the good.

Fire ants have gotten pretty smug in the past 80 years or so, but their beach vacay may be ending. A smaller, more prolific ant is invading fire ant territory. And when combat breaks out between the two, the invader almost always wins.

The new ant in town, the crazy ant (Nylanderia fulva), also hails from South America. It gets its name from its chaotic and erratic movements while foraging for food. It's reddish-brown, about half the size of a fire ant, with long antennae. As it lacks a stinger, you may wonder how it stands up to a fire ant. Answer: a unique gland on its abdomen releases formic acid that deactivates fire ant venom. It rubs this all over its body to form a shield and can also spray it as a weapon.

The result? When crazy ants take on fire ants, they win more than 90% of the time.

It's All Good, Right?
You've heard it many times before—there's no such thing as a free lunch. Crazy ants cause their own problems. They don't build mounds like fire ants, but nest in tree cavities, yard waste, plants, buildings, and rocks. Individual nests are usually smaller than those of fire ants, but may be interconnected to form super-colonies containing millions of individual ants. Crazy ants don't target people. They eat mostly insects and sweet and greasy liquids. But when they come, they come not in single file, but in waves.

Now here's where the story gets really nuts. Crazy ants find the electromagnetic fields generated by electrical devices to be irresistible. If they locate an entrance, they'll pile into it by the thousands, often causing a short-circuit that disables the device. Air conditioners, cable boxes, and electrical boxes are prime targets outdoors. Indoors, people have discovered crazy ants invading computers, televisions, light fixtures, and wall outlets. Ant baits, dusts, and spraying the home's perimeter with insecticide will all kill ants, but crazy ants don't mind walking across the dead bodies of their brethren to come right back. This means repeated treatments as necessary.

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So far, crazy ants seem limited to states along the Gulf Coast, because they're more sensitive to cold than fire ants. With the warming climate, however, nobody knows how far north they might spread. Eventually, you may have a choice to make. Would you rather play with fire? Or would you rather go crazy?