"Fire Ants - Most succesful creature that has ever lived | Full Episode "

This is the realm of the most successful creature that has ever lived. So is this. And here. It has been adapting, evolving for 150 million years. 14,000 species. They are nearly everywhere. Thriving. The ant. This is the story of Solenopsis Invicta. For 80 years, it has been on a ceaseless march across the United States. Racking up $6 billion every year in crop damage, equipment repair, and pest control. Conquering 340 million acres in 13 states. And it's still on the move. Globally. Now, scientists are cracking their ancient secrets to success and survival. We knew that we could speculate all day, but to fully understand the ants, we decided to bring them into the lab and obtain visual data. Enlisting crime scene forensics to track the invaders back to their origins. And breeding winged assassins to hunt them down. One of the questions that I frequently get asked is, what's going to happen when the flies run out of fire ants to eat? How could something so small be so destructive and create alien worlds? With collective behavior and swarm intelligence, it is a super organism. There are 22 known species of fire ants. This is perhaps the most feared, even reviled, of them all. The red imported fire ant. It doesn't belong here in this South Georgia lawn or even on this continent, but it's here to stay. The fire ant is native to the flood plains and savannas of South America. Sometime in the 1930s, they hitched a ride on a cargo ship and were dumped in an Alabama port. Invicta had found the land of great opportunity, a fire ant's paradise. We have been their scornful yet benevolent neighbors ever since. A mature colony can hold a quarter of a million fire ants. Their mounds can reach 18 inches high and are often identified by a freshly tilled look. Inside, an elaborate system of tunnels and chambers extends down into the ground. Like ants the world over, these insects are highly efficient earth movers and clever architects. Climate control and safety are paramount. Ants don't have the internal ability to regulate their body temperature like we can, but they can build and they can mobilize. On cool mornings, workers bring the entire colony, queen, eggs, and larvae up into the sun-warmed mound. In the heat of the day, the ants methodically retreat back down into cooler ground. We instinctively seek shelter from the storm. The fire ant does just the opposite. When rain saturates the soil, their home becomes a death trap. If they don't evacuate, they will all drown. But it's not every man for himself. The queen and helpless brood must be protected. To us, this scramble looks like chaos. It's not. It's organized chaos. Every ant has a job and if ants had a motto, it would probably be girl power. The ant world is run and ruled by females. Each is an exquisite work of art. The colony is almost entirely made up of the workers, all sterile females. A worker begins her career as handmaiden to the queen and nurse to the brood. Feeding and cleaning her highness and offspring is a full-time job. As they get older, workers are promoted to sanitation, excavation, foraging for food, and defense of the colony. These large wing dance are future queens and the colony's only males. Their only job is to wait for nature's call to emerge from the nest for their nuptial flight to mate. When the brief honeymoon is over, the males soon die off. Their job is done. The future queens fly off with a lifetime supply of sperm and establish a new colony. A new queen will only fly a few hundred feet or a few miles to her new home. She can live for eight years and lay hundreds of eggs a day. What began as a local infestation in a port city spread to 530,000 square miles. The fire ant has confounded all efforts to eradicate it or even slow it down. At one time, experts thought the ants could not reproduce where the average temperature was 10 degrees Fahrenheit. Surely winter weather would provide a firewall. They were wrong. Fire ants can survive winters of zero degrees Fahrenheit by hunkering down deep in their nest and expanding their potential range to a quarter of the continental United States. The fire ant would seem unstoppable. The oldest and largest workers are key to the ant's survival. They are the scouts and foragers. It is their job to find food, lots of it, and bring it back to the colony. How do you feed a city of a quarter million? It would take a huge workforce and rock-solid logistics, the fire ant's specialty. Tunnels radiate out from the mound like subway lines as far as 100 feet. On a human scale, this transportation system would traverse a hundred thousand miles. There's an exit every foot or so for foraging ants to pop out or look around. Inside the tunnel, recruits wait for the call to action to help gather dinner. Like us, the fire ants are omnivores, both plant and meat eaters. They're always on the lookout for sugars or carbohydrates and proteins. They aren't picky eaters. A potato chip is a gourmet meal for these oil-loving feeders. Fire ants also have a sweet tooth. Sugar water is an ideal mix of hydration and energy. Sugars power the workers and if it's around, they'll find it. When a scout finds food, she leaves a chemical trail for others to follow. These workers will drink their fill and regurgitate it back in the colony to ensure all are fed. Fire ants are opportunity feeders. They'll take food wherever they can get it. When food is scarce, they'll even hack off the seedlings of new crops for a meal. And if potatoes or peanuts get in the way of tunneling, Invicta is glad to eat its way through. Every year, fire ants cost farmers in the United States $750 million in losses by ravaging seeded fields, damaging irrigation, and injuring livestock. The colony also needs protein, especially for the growing brood. They'll eat any living thing they can take down. This ant is as voracious as it is fearless. Anything that can't fly or run away is likely doomed. Fire ants don't just bite, they sting. First, the ant sinks its mandibles into the prey's flesh, anchoring its body in place. Then it stabs the victim with a hypodermic-like stinger and injects venom. It stings over and over and over again. A cricket's exoskeleton is tough, but its mouth, joints, and abdomen are soft targets. Even the humble roly-poly's built-in armor can't hold the ants off forever. The neuromuscular poison quickly overwhelms small prey. Fire ant venom is highly unusual in the ant world. It's not just an efficient killer of other insects. Queens apply it to their eggs to kill bacteria and fungus from the surrounding soil. Workers will even fling droplets of venom at ants from competing colonies to drive them off or kill them. This battle-tested male anole may think he's earned the right to nap where he pleases, but there is no safe haven in fire ant territory. Junior members of the community will have to keep watch. Everything, everywhere, everyone will be explored in the relentless search for food. Armed and dangerous, Invicta is more than willing to test the metal of a predator 1,000 times its size. It looks like sleeping beauty has awakened, and he doesn't like being bitten on the toe. He won that battle, but he dare not go to war with her sisters. Reptiles that stand their ground are promptly removed from the gene pool. Even large mammals are at risk. Fire ants have been documented killing newborn calves. Deer fawns that instinctively freeze when sensing a threat can quickly find their nose, throat, and lungs clogged with fire ants. Invicta saves its most merciless attack for anything that dares threaten the colony. Prada mound, and workers boil out in a mad rush. The superorganism is like a weapon with a hair trigger. These tiny warriors can pose a serious threat, even to us. Every year, as many as 25,000 people are treated for attacks in the United States. Hundreds are hospitalized. There have been at least 80 documented human deaths from fire ant stings. Most are attributed to victims going into anaphylactic shock from severe allergic reactions to the venom. As the fire ant's territory continues to expand, those numbers will only grow. This ancient ancestor of the wasp seems to have a plan to handle just about anything, we, or nature, can throw at it. A good storm can ruin our day and even threaten our homes. The fire ant is prepared for that too. This time, the water isn't going to stop. A flood is coming. Once again, the fire ant's superorganism instincts kick into gear. Workers quickly open up dozens of new exits and evacuate the young. Scouts scramble to find higher ground or an escape route from the rising water. The search is a dead end, but the ants aren't finished. In minutes, the colony assembles into a raft. The queen and non-swimmers are carefully rounded up. They'll be covered with a protective layer of workers. They will not be left vulnerable to the scorching sun or predators. You are witnessing one of nature's ancient wonders. This is how the tiny fire ant has survived the yearly epic flooding of its South American homeland. It is the only insect known to do this. Raft can float along for months until the water recedes or it hits dry land. The colony disentangles, disembarks, and sends scouts in search of a new home. A knothole will do for now. Just who chooses the new home and how is still a mystery. The precious little ones are whisked away to safety. Rafting has kept Solenopsis invicta alive for eons. Biologists could only guess at how they do it, until now. The ways in which fire ants work together and cooperate as a colony is unlike anything that we as humans are able to replicate today. But I believe that through studying the fire ants, they have a lot to teach us in the areas of engineering, material science, and even robotics. Nathan Mallott, a mechanical engineering student at the Georgia Institute of Technology, analyzes the cooperative behavior of fire ants. Mallott and Professor David Hu decided to put Invicta through a series of experiments to tease out the secrets to their abilities. Fire ant rafting had already been well documented, but not very well explained. We knew that we could speculate all day, but to fully understand the ants, we decided to bring them into the lab and obtain visual data. They came at the red menace as engineers and discovered an entirely new way of looking at the insect. A fire ant colony can respond to threats or challenges by acting like a textile, a liquid, or a building material. A single ant's exoskeleton is partially wetting. This is why when you put a single ant on the water, it will flounder. But when you put a hundred or even a thousand ants onto the water, they link their bodies together, forming a floating raft. If you look closely at the bottom of the raft, you'll see that the ants link together and form a stable base for the rest of the colony to rest upon. The ants aren't simply floating. With all of that weight on a small area, the raft should sink, but it doesn't. The researchers wanted a closer look. They needed to create a snapshot of the event. But fire ants won't sit for a family portrait. A little liquid nitrogen at 320 degrees below zero does the trick. The frozen ant raft is then put through a micro-CT, or CAT scan. It's the same basic technology used in hospitals to look inside our bodies. When you freeze ants in time and then examine the raft, you find there are actually very few holes. Instead, each ant is connected to on average eight of its neighbors using mandibles and the ends of its legs. And this makes for a very strong but dense network. When threatened with drowning, the fire ant superorganism instinctively weaves itself into a kind of waterproof fabric. By linking closely together, the ants create a rough surface that magnifies their water repellency. The raft is far more buoyant than the sum of its living parts. When you push down on this raft, you see that it actually flexes and stretches like a fabric. If you push further, trying to submerge the raft, you find this raft turns into a watertight bowl. In the submerged sphere, the surface tension of the water keeps the water out and the ants inside alive. This surface tension continues to keep the water out up until about eight inches of depth. In human terms, that's nearly 400 feet underwater. The researchers were just getting started. They noticed that the ants seemed to sense how many passengers were aboard. As ants are removed one by one, those on the bottom move up. Without any central command or captain of the ship, the superorganism keeps the raft at a consistent optimal thickness. The fact that the ants always build the same shaped raft is an example of what we call swarm intelligence. We believe that this collective behavior can be applied to robotics. Basically, it's much easier to build a small robot following simple local rules than to build a complex robot that will change shape and perform complex behaviors. When spun in a beaker, the ants instinctively gather into a tight sphere. There are disturbing legends of researchers long past who'd engaged in ant ball fights. Molot and Hu weren't about to try that, but it did align with their observations. When you handle ants, they feel like chewing gum. You can pull them apart, stretch them, and with enough force, you can break them. The ants themselves have a very high strength, so potentially they would have enough force to break off each other's limbs, but they don't. Next up, the microscopic strength test. When sticking to a rough surface, ants can't support as much as 5,700 times their body weight. That could be lethal to rafting on rough water. But when sticking to each other, the fire ant grips its neighbor with only 400 times its body weight. The fire ant seemed to know the physical limitations of their bodies. They carefully modulate the force of their grip so that when their outside forces, such as wind, gravity, or waves, they release each other before ripping off each other's legs. Researchers noticed other peculiar behaviors. The superorganism could also act like a liquid. The ants inside this funnel are being pulled downward by gravity, but they don't freefall like grains of sand in an hourglass. Their controlled grip on neighbors allows the colony to flow like a thick fluid, gently touching down on the surface below. Each fire ant is hardwired with seemingly simple commands that allow the colony to navigate complex terrain. Just as a fluid sticks to objects at the surface and flows across gaps, the fire ant colony controls its descent. When clumps of ants fall, they land like sticky drops, dispersing the energy of the fall, but keeping the colony together. The fire ant's legendary strength is in its numbers and its collective behavior. There are already other roboticists able to build small robots that follow simple rules and can link up with other robots to perform complex, cooperative behaviors. Imagine we have a sewer drain where we can drop simple ant-like robots down the drain, and these ant-like robots will link together at the bottom of the sewer, building a larger robot that can perform human tasks such as inspection and repair. By studying the behavior of fire ants, we can learn a basic blueprint for how such robots need to coordinate and behave. For social creatures, communication is critical. It allows us to share information, to seek help, warn others of danger, organize. Communication is power. We use sounds, words, language. A fire ant uses chemicals called pheromones, the foundation of their society. When a foraging ant finds food too large to take back to the colony, she lays down a trail with her stinger. The better the food, the stronger the trail. The ant's antennae serve as its nose, detecting the chemical message. By releasing different amounts and different types of pheromones, the ant spread the word that dinner is this way, it's time to move the colony or attack the intruder. The chemicals also tell the colony who's the queen, when her babies need help, when it's time to mate. Perhaps 20 different messages in all. The fire ant's antennae are so sensitive, one teaspoon of recruitment pheromone is enough to create an ant trail 120 million miles long. That's 5,000 times around the earth. Like many insects, fire ants have two compound eyes made up of dozens of lenses. They lack the resolution of a single lens eye such as ours, but they have a far larger viewing angle and are excellent for detecting motion. The ant has three more eyes on top of its head for navigation. Fire ants orient themselves by the sun. If you replace the sun with a revolving light in a laboratory, ants wander around aimlessly, never laying down a trail to the food. The fire ant doesn't just enjoy our ham sandwiches, they have a taste for modern conveniences. Traffic lights are a popular destination. The ants are attracted to electrical fields, chew on wiring, and get electrocuted for their trouble. The fried ants give off alarm pheromones, fatally attracting more ants. Their electrical repair bill runs into the tens of millions every year with burned out well pump switches, airport runway lights, and electrical outlets. In Texas, air conditioning technicians have reported that one-third of summertime repairs are due to fire ants shorting out electrical components. Unraveling fire ant behaviors can take decades of research. It also requires a technique known to craftsmen as far back as 3200 BC. It works just as well today. But instead of creating plowshares, swords, or art for the king, it will reveal the invisible empire of the fire ant. A small hole is made in the center of the mound, carefully exposing some larger tunnels down into the nest. Several pounds of molten wax are carefully poured into the hole. The liquid quickly flows to the farthest reaches, instantly entombing the occupants. In the fire ant business, talcum powder is like kryptonite. It clogs up and dries out the tiny hairs on an ant's feet. If they can't climb you, they can't sting you. The nest is dug from the ground. It will take hours of painstaking work to clean away the dirt and roots. To us, this may look like little more than tangled string, an alien puzzle. It is a masterpiece of civil engineering. The spiraling tunnels interconnect chambers used to store eggs, raise young, rest, process food. It is a home, a fortress, a nursery, a highway system. The building plans are encoded in the fire ant's very DNA. Where they go, it goes. The global invasion is well underway. We provide the machines and a free ticket to ride. Traveling in wooden pallets, nursery stock, lumber, used earth moving equipment, nearly anything, a single newly mated queen can establish a beachhead in virgin territory. Fire ants have been found in the Caribbean, New Zealand, Australia, Taiwan, China, Macau, at least 11 countries. No one knows the full potential range of Invicta, but studies of climate and water availability indicate that as much as 50 percent of the earth's surface is habitable by the ants. You must hear the personal accounts of all of us, the farmers, housewives, sportsmen, and scientists like myself. We're all deeply concerned with the imported fire ant problem. The United States government waged two all-out wars on the fire ant from 1957 to 1975. Don't think the past just limits itself to wildlife and agriculture. Construction gangs and utility crews have tried various ways to avoid us. Trouble is, fire ants can't read. Fueled by a powerful mix of politics and public hysteria. Now don't get the idea that our homes are safe from attack by the fire ant. More than 400 million pounds of poisoned bait was spread over millions of acres. Provided all people cooperate, there will be no damage when the airplanes or ground equipment go to work. No damage that is, except to the fire ant. The results were disastrous. The poisons were indiscriminate, killing honeybees, birds, cattle, marine life, fire ants, all ants. Worse yet, with all competitors wiped out of an area, the prolific fire ant soon moved back in and dominated. By the time the eradication campaigns ended in 1975, Invicta had more than doubled its territory. The staggering amounts of poison had only strengthened the fire ant's iron grip on the United States. As Invicta began invading other countries, the question became, where are they coming from? The United States or South America? Or could the ants be jumping from country to country with global trade goods? Knowing the ant's travel route could help authorities stop, or at least slow, their march into new territory. The answer was locked away inside the ants themselves. Dr. Duane Shoemaker was determined to wrest it from them, one ant at a time. Shoemaker and his team gathered ants from the newly invaded territories, ground them up, and extracted their DNA. Specific markers in the ants' genes would identify which colonies, which queens, had produced the fire ants turning up overseas. The results were clear. These are the same types of markers that are used for paternity analyses and crime scene forensic analyses in humans. And our results consistently and unambiguously indicated that the U.S. is the immediate source population of fire ants found in all introduced areas, including China, Taiwan, and Australia. But Shoemaker didn't stop there. He compared the findings to genetic samples from more than 2,000 colonies in 75 sites worldwide. And what they told him surprised nearly everyone. The fire ant invasion hadn't started in Brazil, as most biologists thought. The genetic trail led back to the flood plains of Argentina. We sampled a large number of fire ant mounds from different areas in South America, and our results clearly show that there have been at least two introductions of fire ants into the U.S., both of which come from an area in northeastern Argentina. This area lies along the Paraguay River, which represents a possible route of introduction of fire ants into the U.S. Perhaps wood or ship ballast from the Paraguay River into the ocean, then to the U.S. Exactly where the invasion had originated 80 years ago was becoming important. History had shown that eradication was extremely difficult and rife with unseen consequences. Dr. Sanford Porter had long since decided it was time to put down the hammer and look for a new tool. He found it eagerly waiting back where the story of Solenopsis Invicta began, and it had long been perfected by nature. This tool was custom-made to kill fire ants, and it's no bigger than the head of a pin. These forward flies specifically target fire ants, and the reason they do that is because they seek after the smell of the fire ant, they need an ant of the right size, and they have to look like fire ants. They only will attack fire ants, and only fire ants that come from South America, even fire ants that are native here in the United States, are not suitable hosts for the flies that we're bringing up from South America. Porter and his colleagues identified five forward flies that prey on the fire ant and nothing else. These workers are toiling away in a high-tech fly factory here at the USDA's Animal and Plant Inspection Service in Florida. The concept is simple and ingenious. The ants have nowhere to hide their brood but the cup on the tray, but every 10 minutes they're forced to relocate the babies. They are always on the move and always vulnerable to the attackers hovering above them. Where humans carpet-bombed the fire ant with poison, the forward fly prefers a surgical strike, literally. The flies are drawn to ant mounds by their pheromones. The ants sense the danger and release more pheromones, gathering more flies. It's as if the ants are calling in an airstrike on their own colony. If fire ants have nightmares, they look like this, the business end of a forward fly. These male flies hovering above the ants are waiting for the females to arrive. In forward flies, patience is not a virtue. They only live for a few days, so everything happens fast, very fast. They mate in the blink of an eye. And so the females will be following around tracking the fire ant. The males, meanwhile, will be tracking the females and if they can find the female, they'll grab the female out of the air, they'll mate in the air and as they fall to the ground, they need to complete the mating and then break apart because if they're slow at it, the fire ants will catch them and eat them. We have several dozen species of these flies, but each of these species of flies has an ovipositor that fits into the some part of the ant like a lock and a key. And in each of these ovipositors, when the fly flies in, she'll latch onto the fire ant in just the right spot. In a fraction of a second, she injects the egg into the body of the ant and then flies away. There is no escape. She strikes with incredible speed and precision, injecting an egg into the ant's body. It is a death sentence. In days, the egg hatches and a microscopic maggot crawls up into the ant's head. Sister ants suspect nothing until the maggot releases an enzyme decapitating its host. The maggot then eats the dead ant's brains, muscle tissues, bodily fluids and all, increasing 100 times in size. Soon, a new forward fly emerges and the cycle starts again. One of the questions that I frequently get asked is what's going to happen when the flies run out of fire ants to eat? And what I can tell you is that they'll simply die. Every year, technicians harvest 3 million fire ant heads and their tiny tenants for shipment across the United States. This mass breeding program has successfully established forward flies in 11 states, a growing air force with a singular mission, kill fire ants and make more flies. The forward flies alone are not going to solve our fire ant problem. When we go down to South America, what we find is that fire ant populations there are about one-fifth to one-tenth of what they are here in the United States. And we think that that's because of escape from natural enemies. So our goal is to bring up enough of the right kind of natural enemies and safe natural enemies that we can tilt the ecological balance in favor of the native ants here. Microbial spores, viruses and parasitic ants have been keeping them in check for millennia. Those who study fire ants will readily admit that the definitive book on Invicta's survival control and management was written by mother nature long ago. Every breakthrough in research is yet another glimpse at another page. Some say the fire ants story isn't all that different from ours. They are highly social and cherish their young. They communicate and organize on a massive scale. We are highly intelligent, but they can do the seemingly impossible. We build great cities. They build great empires. Fire ants are late comers to global invasion, but they have never been defeated. It has also been said that if humanity destroys itself in a nuclear war, cockroaches will inherit the earth. Probably not.