9 Things You Didn't Know About Leafcutter Ants

Leafcutter ants, as their name suggests, are those often found parading leaf pieces along the rainforest floor of Central and South America. The name is actually an umbrella term for dozens of species belonging to the two genera Atta and Acromyrmex. Characterized by their spiny, reddish-brown bodies and long legs, leafcutter ants — also called parasol ants for the way they carry their leaves like parasols above their heads — are incredibly hardworking fungus farmers, and fascinating creatures all around. From their sprawling, complex colonies to their exceptional physical strength, discover the most interesting facts about leafcutter ants.

1. Leafcutter Ants Don't Actually Eat the Leaves

The sight of these insects, marching en masse with leafy greens held overhead, would naturally lead one to think they're preparing a salad bar of epic proportions. However, the ants don't eat the leaves; they feed them to their crops instead. A University of Montana study says they put them into "colony dumps," similar to a landfill or compost pile, and that those dumps "create ideal conditions for the bacteria that make nitrous oxide," a greenhouse gas. The decomposing leaves then help to fertilize the fungus gardens on which the ants sustain.

2. They Have Specially Adapted Jaws for Sawing

The tiny critters cut leaves (and flowers, and other foliage) into more manageable pieces using nothing but their own jaws. They have special chainsaw mandibles — unique to this species of ant — that can vibrate a thousand times per second, according to the U.S. Fish & Wildlife Service. That's three times the gravitational force. The high-pitched sound this vibration makes also causes the leaves to stiffen up, making them easier to cut.

3. They Can Carry 50 Times Their Weight

In addition to their profoundly powerful, chainsaw-like jaws, the bodies of leafcutter ants are equally marvelous. In fact, they're one of the strongest animals on earth, able to carry up to 50 times their own weight. That would be like an average-sized human carrying a minivan in their mouth — while moving at a speed faster than Usain Bolt's sprint, at that.

4. They Live in Massive Colonies

Leafcutter ant colonies can house up to 10 million ants, not including the space needed for all their fungus gardens, nurseries, trash chambers, and other necessities. The largest nests can have thousands of chambers — some up to a foot or more in diameter — covering a space of 320 to 6,460 square feet in total. The size and complexity of their societies is rivaled only by humans.

5. Each Has a Different Role

A leafcutter ant colony is composed of insects that, like humans, fill unique and essential roles. There are workers, soldiers, trash gatherers, and a single egg-laying queen, but one of the most fascinating is the role of the minim ant. These are the tiny protectors whose job entails riding on the leaves and plucking off dangerous parasites en route to the colony. They also protect the leaves from parasitic flies and wasps.

6. It's Difficult for Them to Start New Colonies

Starting a new colony isn't an easy job, and the burden falls solely on the young queen. Winged ants — both female and male — leave their nests in large numbers to take part in what's known as a "nuptial flight" (or "revoada"), where they mate with ants from other nests. A female and potential queen needs to mate with several males, then return to the ground to find a place for her fungus garden and future colony. Only about 2.5 percent of queens succeed in this feat.

7. They're Mighty Hard Workers

It's no wonder why the leafcutter ant is widely considered a major crop pest. They're diligent, tireless, and incredibly hardworking critters, able to strip a tree of every last bit of foliage in less than 24 hours. Studies show that more than 17 percent of leaf production by plants surrounding a leafcutter ant colony goes directly into their colossal, fungus-growing nest.

8. There Are More Than 40 Species of Leafcutter Ants

"Leafcutter" is the broad name that describes 47 known species of leaf-chewing ants. They fall into two genera, Atta and Acromyrmex, which have subtle differences, like their number of spines (the former has two pairs while the latter has three) and the size of the queen (that of the Acromyrmex genus is characteristically smaller). Atta ants are more polymorphic, meaning they have more genetic variation.

9. They're Extremely Important to Science

According to the U.S. Fish & Wildlife Service, studies of leafcutter ants have contributed to scientific advancements in pharmaceuticals and clean energy alternatives, due to their intake of cellulose, which they can't themselves digest but their fungus crops help to break down. Recent discoveries of a sort of antibiotic-producing bacteria that they coat their bodies in has played an integral role in research on human antibiotics as well.