Fire Ants Are Disappearing Across Texas — Scientists Found What Came Back to Hunt Them

[00:00:00]Fire ants is threatening agriculture and livestock in New South Wales. In a [music] big change of pace, the species has spread nearly 100 kilometers.

[00:00:07]>> For decades, fire ants have spread across Texas. They send more than 80,000 Americans to emergency rooms every year and cause over $1 billion in agricultural damage across the state.

[00:00:20]For more than 40 years, no chemical program has been able to stop their invasion across 30 million acres. Then something unexpected happened.

[00:00:31]Scientists found fire ant colonies collapsing across three pasture zones without poison or any human help. And the discovery shocked them. The reason behind was a 5in lizard that can shoot blood from its eyes. It had disappeared for 40 years before quietly returning on its own. So, how could such a small lizard fight one of the deadliest invasive ants in America? In this video, we'll uncover the surprising story behind this incredible comeback. Let's dive in. Silent [music] Texas invasion.

[00:01:06]Long before scientists noticed fire ants disappearing, those ants had already changed Texas forever. The story started during the 1930s at the Port of Mobile, Alabama. Ships arriving from South America carried more than just [music] cargo. Without anyone realizing it, red imported fire ants arrived with them.

[00:01:28]Within a few years, they spread into nearby land. By the 1950s, they had reached Texas, where the warm weather and open ground gave them everything they needed to grow. Even more important, the ants left behind the natural enemies that controlled them in South America. Nothing in Texas could slow them down. One colony could contain between 100,000 and 500,000 workers. A single queen could lay around 1,500 eggs every [music] day. In badly affected pasture land, scientists counted between 100 and 200 mounds in just one acre. The invasion grew until it covered nearly 30 million acres across the state. What followed turned a small invasion into one of the biggest ecological disasters [music] Texas had ever faced. And what followed turned this seemingly small invasion into one of the biggest ecological disasters Texas had ever faced. Fire ants quickly became a serious problem for both people and wildlife. Every year they sent more than 80,000 Americans to emergency rooms because of painful stings and dangerous allergic reactions. Their impact spread even farther across Texas. Fire ants crawled into electrical boxes and damaged equipment. They built hard mountains along roadsides, in playgrounds, at airports, inside cemeteries, and across sports fields.

[00:03:07]Farmers watched cattle avoid large areas of grazing land because aggressive colonies covered the ground. Those losses added up to more than $1 billion every year across the state. People fought back with every method they could find. They spread bait across fields.

[00:03:26]They treated individual mounds. They used growth regulators and powerful insecticides.

[00:03:33]Each treatment lowered fire ant numbers for a short time, but the success never [music] lasted. New colonies always returned from nearby land within one to three seasons. Their numbers recovered faster than people could stop them.

[00:03:50]After decades of trying, [music] scientists reached a difficult conclusion. No chemical program had found a lasting answer, and many people believed the invasion had become permanent. But while everyone searched for a better way to defeat the fire ants, [music] something much quieter was happening across the same landscape.

[00:04:12]A native animal that had shared Texas for millions of years was slowly fading from view. Yet almost nobody realized that its disappearance would become one of the most important parts of this entire story. Forgotten native predator.

[00:04:29]The missing animal was not large. It was not fast. Most people could hold it in one hand. Yet for millions of years, it had quietly lived across Texas without asking for attention.

[00:04:44]Its name was the Texas horned lizard.

[00:04:48]Today, it is the official state reptile of Texas. It grows only 3 to 5 in long.

[00:04:55]Its body [music] is flat and covered with sharp spines that help it blend into dry grass, rocky ground, and dusty soil. At first glance, it almost looks like a small dinosaur frozen in place.

[00:05:09]But the feature that made this little reptile famous was something far stranger than its appearance. The Texas horned lizard carries one of the most unusual defenses in the entire animal kingdom. When a coyote, fox, or even a domestic dog attacks, the lizard can shoot blood from its eyes. The stream can travel up to 4 feet. It sounds unbelievable, yet it is completely real.

[00:05:38]Surprisingly, this strange defense followed a precise biological process that scientists later uncovered. The lizard tightens muscles around the veins in its head. Blood pressure builds behind its eyes until tiny membranes break open. The blood carries a chemical that tastes terrible to canine predators.

[00:06:01]During [music] controlled studies, coyotes quickly reacted by shaking their heads, gagging, and refusing to attack the lizard again. Now, researchers wanted to understand this strange behavior better. Scientists from the USDA discovered something even more surprising. The horned lizard almost does not use this defense against people. [music] Researchers spent years trying to trigger it without success.

[00:06:29]They finally trained a dog to gently paw and nibble the animals before the bloodshooting defense appeared. The lizard could tell the difference between a human and a canine predator through the pattern of touch on its skin. And this recognition accuracy came from millions of years of evolution.

[00:06:48]This animal had not simply learned these behaviors. It had evolved over millions of years. Every [music] part of its body had slowly adapted to survive in one very specific environment. Its greatest strength, however, was not its defense.

[00:07:05]It was its diet. An adult Texas horned lizard needs between 60 and 100 harvester ants every day. Some studies suggest the number can be even higher.

[00:07:17]These large native ants move along predictable trails and provide enough food for the lizard to survive. The horned lizard evolved alongside them for millions of years. It even developed resistance to harvester ant venom. Thick mucus inside its mouth and throat trapped the ants before they [music] could sting. High-speed video research published in 2021 showed the lizard striking the ants thorax with amazing accuracy before pulling it into its mouth headirst.

[00:07:52]Every part of this remarkable hunter had been shaped for one purpose. That incredible specialization would soon become its greatest weakness. food web collapse. Everything changed when red imported fire ants spread across the same ground. Unlike native ants, fire ants did not share territory. They took it. [music] Their workers searched for harvester ant colonies, surrounded them, killed their queens, and claimed the land as their own. In many places, an entire colony disappeared within a single season, and the loss spread farther than anyone expected. Across the Edwards Plateau, harvester ant numbers dropped lower every year. The change looked small at first, one empty trail, one missing colony, then another.

[00:08:47]Slowly, the food that had supported the horned lizard for millions of years began to disappear from pasture after pasture. However, the horned lizard could not simply choose something else to eat. Its body had spent millions of years adapting to one reliable food source. It had never needed a backup plan because nature had always provided enough harvester ants to survive. As those ants disappeared, the lizard found fewer meals each day. Many stopped producing young. Others vanished from places where they had lived for generations, but people hardly noticed the change. Children who caught horned lizards in the 1950s and 1960s grew older. Years passed. Their own children rarely saw one outside a picture book or museum display. The official state reptile of Texas slowly disappeared from everyday life without making headlines.

[00:09:48]Unfortunately, human efforts to fight the invasion soon began destroying the very food the lizards still depended on.

[00:09:57]People continued fighting fire ants with pesticides across farms and ranches.

[00:10:03]Those treatments often killed native ants along with the invaders.

[00:10:08]Many land owners could not tell the difference between Texas red harvester ants [music] and imported fire ants.

[00:10:16]They poisoned the very colonies the horned lizard depended on. Now, one problem led to another. Farmers cleared weeds to improve grazing areas. Those weeds had produced seeds that fed harvester ants. Fewer seeds meant fewer native ants. Fewer ants meant even [music] less food for the horned lizard.

[00:10:41]One small change led to another until the entire food web weakened across the landscape. At last, Texas recognized the danger. The state protected the Texas horned lizard during the 1970s and officially listed it as a threatened species. In 1977, the new law stopped people from harming the animal directly. Yet, the protection solved only part of the problem. Saving the lizard could not restore the food it had already lost. Scientists slowly realized they faced something much bigger than protecting one reptile. An entire ecological relationship had broken apart beneath the grass, rock, and soil of Texas. The animal still knew how to survive. The land simply could no longer support the life it had evolved to live. Now researchers faced a question that seemed almost impossible.

[00:11:43]If the food web had collapsed, rebuilding the lizard alone would never be enough. The entire system would have to come back together before Texas could truly bring its forgotten survivor home again. Unexpected scientific return. In 2011, the Fort Worth Zoo launched a conservation program unlike anything attempted before. The zoo joined Texas Parks and Wildlife and Texas Christian University with one goal. They wanted to rebuild an entire ecosystem instead of simply returning lizards to the wild.

[00:12:22]Now, the work began with a difficult challenge. Nobody had ever successfully bred Texas horned lizards in captivity.

[00:12:31]Years of decline meant researchers had very little information about how to raise them. Senior curator of ectotherms, Diane Barber and her team started developing breeding methods from the ground up. Every successful [music] hatchling became another step toward bringing the species back. And the first release revealed a new problem.

[00:12:54]Researchers released adulthorned lizards into the Mason Mountain Wildlife Management Area in Mason County. Many struggled to survive because they entered unfamiliar ground where predators quickly found them. The disappointing results forced the team to rethink the entire program. At last, a better solution slowly appeared. Instead of releasing adults, researchers began releasing hatchlings.

[00:13:22]The young lizards adapted more quickly to their surroundings and found shelter soon after entering the wild. Their survival steadily improved, giving conservationists fresh confidence that recovery might still be possible. The next breakthrough came from genetics.

[00:13:41]Professor Dean Williams at Texas Christian University led genetics research that revealed three different Texas horned lizard populations across the state. One lived in the western deserts. Another occupied the northern plains. The third survived in the southern plains. That discovery showed why scientists could not move lizards freely between regions. Each population carried genetic traits [music] shaped by its own environment. Williams and his students used DNA barcoding [music] to study the insects found in the horned lizard's diet. They also examined wild and captive populations and documented habitat use through photographic surveys. Every new discovery helped improve future releases. Finally, the years of careful work produced encouraging results. In 2021, hatchlings released at Mason Mountain during 2019 became the first reintroduced Texas horned lizards ever to breed successfully in the wild. The achievement proved that the animals could survive, reproduce, and begin rebuilding their own population without constant human help. Luckily, the effort began paying off. Nature fights back.

[00:15:00]The recovery of the horned lizard was only part of the story. Across those same years, scientists [music] searched for another way to slow the fire ants themselves. They understood one important fact. Red imported fire ants had become so successful because they had left their natural enemies behind in South America. If those enemies could return safely, the balance might begin to shift. That idea led scientists in a very different direction. In 1994, two research teams began studying tiny forehead flies as biological control agents. One team worked at the USDA Agricultural Research Service Laboratory in Gainesville, Florida. The other worked at the University of Texas at Austin. Both groups believed nature might already have the answer. What happened next made these tiny flies unlike anything scientists had seen before. South American forehead flies measured only 1 to 2 mm long. They were much smaller than the fire ants they hunted. Yet every female fly carried an ability that made scientists pay close attention. However, the attack lasted only seconds. A female fly hovered above a disturbed fire ant mound or a busy foraging trail. She picked a single worker and quickly injected one egg into its body before flying away.

[00:16:27]Unexpectedly, the infection followed a path that scientists found almost impossible to ignore. The egg hatched and the tiny larvae slowly moved into the ant's head. It fed on muscles and nervous tissue for about 2 weeks. During that time, the infected worker wandered away from normal colony activity.

[00:16:48]Researchers described this stage as zombie behavior because the ant no longer behaved like the rest of the colony. What happened next was the most shocking part of the entire life cycle.

[00:17:00]The growing larvae released an enzyme that separated the ant's head from its body. It completed its development inside the detached head before emerging as a new adult fly ready to repeat the cycle. Hidden ecological balance. Many people believed the Texas horned lizard had returned to hunt fire ants. That sounded like the perfect answer. Yet, the real story proved far more interesting. The lizard rarely eats imported fire ants at all. Its body evolved to handle native harvester ants.

[00:17:36]Not the powerful venom of fire ants.

[00:17:39]Millions of years of evolution prepared it for one food source. And that never changed. Every day, an adult horned lizard feeds at the entrance of a native harvester ant trail. It can eat between 60 and 100 harvester ants a day. At first, that seems harmful to the colony.

[00:18:01]Scientists [music] discovered the opposite. The lizard helped keep the colony smaller, stronger, and easier to defend. Instead of spreading farther, the ants focused their energy on protecting the territory they already held. And that small difference changed everything. A colony with a shorter boundary needed fewer workers guarding distant edges. [music] More workers stayed near the queen, cared for young ants, and defended the nest entrance.

[00:18:33]Fire ant scouts found fewer weak points to attack. Native harvester ants held their ground more successfully, while imported fire ants expanded more slowly across the same landscape. Field observations by biologists started telling a different story. Fire ant colonies faced stronger competition instead of empty ground.

[00:18:58]Scientists realized the horned lizard was not controlling fire ants by eating them. Instead, it quietly changed the relationship between two competing ant species in a way no chemical treatment had ever achieved. Now scientists needed proof that this idea was happening outside the laboratory. That is why wildlife surveys across the Edwards Plateau became so important. For years, one wildlife biologist returned to the same pasture corridors near Kurville and carefully recorded every change.

[00:19:35]Scientists [music] continue searching for new tools. In 2025, researchers from Peing University and Cornell University published GAN drive research that could one day work alongside existing biological control methods. 40 years of chemical programs reduced fire ants only for a short time before new colonies returned. Biology succeeded where chemistry repeatedly failed because it restored relationships that already belonged to the land. Nature was never creating something new. It was quietly restoring something ancient that had worked for millions of years. In the end, nature never forgot how this land was supposed to work. It only needed the chance to restore the balance that had existed for millions of years. What do you think is the most powerful lesson from this story? And could restoring nature be more effective than relying only on chemicals to solve problems like this? Let us know your thoughts in the comments below. If you enjoyed this video, don't forget to give it a thumbs up. And if you want more incredible mysteries, discoveries, and true stories like this, be sure to subscribe to the channel. Thanks for watching and we'll see you in the next video.