Huge pythons are taking over part of the state, slithering right into people’s backyards. And now Florida is declaring open season on the predators. >> Watch it. Watch it. Pull him. >> Oh man. >> For a long time, the Everglades looked normal on the surface. The grass kept rising. The water kept moving. And the marsh sounded like it always had until it didn’t. Scientists began noticing long stretches of land that felt too still, as if something had quietly cleared the place out. When a planned

burn finally cleared the field, the real culprit stepped out of the ash. Massive Burmese pythons had taken far more of the Everglades than anyone realized. >> Burning in the Everglades, people miles away from the flames, saying they can see and even smell the fire. when fire revealed the truth about the Everglades. Some mornings in South Florida start with the smell of smoke. Out past the houses and the long straight roads, a low gray band hangs over the horizon. If you follow it, you do not find a

wildfire racing out of control. You find trucks parked on a levey, engines idling, and a line of people in yellow shirts and hard hats walking along the edge of the grass with metal cans in their hands. They are here to set the Everglades on fire on purpose. Each person carries a drip torch, a metal can with a curved spout. When they tilt it, drops of burning fuel fall into the dry sawrass. Little flames grab the dead leaves and start to creep away with the wind. In a few minutes, all those dots

of fire join into one long orange stripe moving across the marsh. Crews from Everglades National Park and state fire staff watch from the safe side of the line. They do this because the park now runs one of the biggest planned fire programs in the whole national park system, burning a little over 100,000 acres in a typical year to keep this place working the way it should. Fire looks violent, but here it is also part of how the wetland stays alive. Long before there were fire trucks or weather apps, summers storms rolled in from the

Gulf and from the ocean and dropped lightning into dry grass at the end of the dry season. Those strikes started fires that crawled through sawrass and other marsh plants, burned off old stems, and then slowed when they hit deeper water. When the rains returned, new plants pushed up through the ash. Over thousands of years, plants and animals grew used to that rhythm. Fire opened clogged channels, let water move, and kept trees and shrubs from turning open marsh into a solid wall of brush. People changed the pattern. Canals were

cut. Levies were built. Water was held high in some basins and drained away from others. Towns and farms pushed into the edges of the marsh. Now, a lightning strike near a road or a neighborhood cannot just burn until it runs out of fuel. Crews have to put it out to keep people and property safe. At the same time, when fire stays away too long, dry grass, branches, and fallen stems pile up. If all of that lights at once on a windy day, the blaze can be far more intense than the old slowburns that used

to walk across shallow water. That is why so much planning happens before a single drip torch is tipped. Months ahead of time, staff from Everglades National Park, the Florida Forest Service, and the South Florida Water Management District look at maps and satellite images and past fire records. They mark patches where grass has built up for many years, where shrubs are creeping into open prairie and where a burn would help thin out dense fuel. Then they wait. The right window is a narrow one. The air needs to hold some

moisture so the fire will not bake live trees and deep roots, but the grass must be dry enough that the line will carry. The wind has to be strong enough to push smoke away from highways and towns, but not so strong that flames race out of the planned unit. Water levels should be low enough to let crews walk, but not so low that the soil layer starts to dry too deep. When all of those pieces line up, the call goes out and trucks roll. Dry sawrass burns with a harsh ripping crackle as if someone is tearing big

sheets of paper over and over right next to your ear. The first things to move are the smallest. Grasshoppers spring up and dart away. Spiders drop from their webs and scramble for damp pockets in the soil. Snakes that hunt frogs and mice slip toward wetter ditches. Birds see an opportunity in the chaos. Herands and egrets hurry along the edge of sloughs with their heads low, grabbing insects and small animals that try to flee the heat. Vultures circle higher, riding the rising warm air. Every so

often, something larger breaks from the grass. A rabbit makes a quick dash to a strip of unburned reeds. A raccoon splashes into shallow water. Once the main firefront has passed, the world behind it is almost unrecognizable. Sawrass stems that stood shoulder high that morning are now short, charred stubs. Without tall grass hiding everything, you can finally see the shape of the land. Small dips and ridges stand out. Old animal paths show as smooth lines across rough ground. Your own bootprints are clear in the ash. In

a truly crowded marsh, you would expect to see fresh marks from rabbits, small hoof prints from deer, hand-shaped impressions from raccoons, in some burned prairies in the greater Everglades today. The thing that stands out is how often these footprints are not what people see. Biologists and fire staff talk about walking long stretches of cooling ash and finding only a few bird tracks, maybe a trail from a turtle, and then here and there, the wide drag of something much heavier that has moved through. The heavy marks

belong to the new top hunters. On most days, even they are invisible. Burmese pythons, big constrictor snakes from far away, are now firmly settled across much of the greater Everglades system. In tall sawrass and shallow water, they slip under mats of dead stems, press into root tangles, and lie still. Their skin is patterned in blotches of brown and tan that match broken sunlight on mud and water. They are ambush hunters, which means they prefer to wait in one spot for long periods rather than move

around in the open. Surveys by federal scientists have found that even when these snakes are present, people almost never see them. One study put the chance of spotting a python during a standard search on the ground at well under 1 in 20. Fire changes that, at least for a short window. When the grass and the thick layer of dead stems at the base burn away, the same pattern that once hit a snake now makes it stand out. On black ash, a long pale brown body looks like a rope laid across a dark table.

The snakes do not spread themselves evenly across the black ground. They gather where there is still a little cover and a little shade. Canals that surround the burn area turn into quick escape routes and resting spots. Clumps of trees in the marsh, often called tree islands, become crowded safe zones where snakes, birds, and other animals try to ride out the heat together. When the land between those islands has been burned down to short stubble, the paths between them look like dark highways.

Follow those paths and people often find more snakes than they were ready for. These burn scars do more than reveal snakes. They reveal absences. Years of road counts and camera work inside and outside the main snake range had already told scientists that something was going wrong. Along the same night routes inside the park, the number of times drivers saw common mammals dropped to a small fraction of what they used to record. While roads outside the main snake areas still showed many of the same animals, all of this is happening

on only a part of a huge system. Everglades National Park alone covers about 1 and a half million acres. The broader Everglades outside the park adds many more. In a given year, the park’s fire program might treat a little over 100,000 acres with planned burns. That is a lot for one crew, but it is still only a slice of the whole wetland. Large stretches of sawrass, mangrove, and tree islands do not see planned fire in a given season. In those unburned spaces, snakes can stay hidden under tall grass

and deep thatch, and the loss of small mammals is easier to miss. When a single burned unit shows almost no small tracks and more big snakes than anyone expected, it hints at how much might be happening out of sight in the rest of the marsh. Fire is still doing the basic work it always did here. By cutting back old stems and brush, it lets new green grass sprout once the summer rains return. Research in South Florida wetlands has found that burns over shallow water can give a short boost to tiny algae and small fish, which then

feed waiting birds and other animals that move in. In that sense, the Everglades still knows how to bounce back from heat and ash. Charred stalks turn bright green in a matter of weeks. Pools fill, herand egrets, and stors find new feeding spots in the fresh growth. What has changed is the mix of animals sharing that reborn ground. In places where large non-native pythons have settled in, the plants can recover while parts of the animal community stay thin. The hard question for the people who work this land is how it ended up

this empty between the blades of grass. To get those answers, scientists had to step away from the smoke and look backward. They had to trace when these giant snakes first started showing up in South Florida. Follow how they spread from one corner of the map to many, and measure how three long decades of quiet growth turned the Everglades from a river of grass into python country, where the python takeover really began. In the late 1970s and 1980s, a new trend took hold in South Florida. Pet shops

around Miami began stocking glass tanks with tiny patterned snakes from Southeast Asia. As hatchlings, Burmese pythons are barely longer than a forearm. They are slim, bright, and curious, and they looked like an easy way to own something wild. For a while, that choice seemed harmless. The problem is that these snakes never stop growing. Within a few short years, that baby snake can turn into a thick, muscular predator longer than most people are tall. In captivity, many Florida pets passed 10 ft and some pushed well beyond

that. Wild pythons caught in the Everglades today often measure between 10 and 15 ft with some record animals close to 18 ft long and weighing well over 100 lb. They need rabbits, chickens, and even small pigs to stay fed, and they are powerful enough to injure the person trying to handle them. At that point, a lot of owners realized they were completely out of their depth. Some people drove their snakes to animal shelters or zoos and begged staff to take them. Many others took a different route. They loaded the python into a

car, drove out to the edge of the wetlands, opened the lid of the tank, and watched the snake slide out into the grass. They told themselves that a big, healthy snake would be happier in the wild than coiled in a small living room. What they really did was put a top-of-the-line ambush hunter into a place that had no idea how to deal with it. Then, nature added fuel to the fire. In late August of 1992, Hurricane Andrew slammed into South Florida as a category 5 storm. >> 1992. Let me show you what it looks like

in the form of Hurricane Andrew. A very strong hurricane making its way on shore right now. Landfall again. The eyewall is now well on shore across the South Dade County. >> The wind ripped apart houses, malls, and industrial parks. It also tore through reptile breeding facilities and roadside zoos that held large numbers of exotic snakes. Reports from that time describe smashed buildings and broken cages with nothing left inside them. No one can count every single animal that escaped in that chaos. But wildlife biologists

and state agencies now agree that pet releases and storm escapes together seated a wild python population that began to grow quietly in the southern tip of the state. The place those snakes landed could not have been more perfect for them. The greater Everglades is warm, wet, and full of food almost all year. Shallow river of grass marshes, tree islands, mangrove swamps, and man-made canals all sit close together like different rooms in the same huge house. In their native range in Southeast Asia, Burmese pythons live in

flooded forests, rice patties, and river edges. South Florida feels very similar. There is no native predator in the greater Everglades that specializes in hunting giant constrictors. Alligators and pythons sometimes kill each other, and people have seen each one swallow the other, but that is occasional combat, not real population control. When researchers open the stomachs of captured pythons in Florida, they find marsh rabbits, raccoons, apossums, waiting birds, songirds, alligators, and even bobcats. Reproduction turns that

hunting machine into a multiplying problem. A single female python can lay somewhere around 50 to 100 eggs in one nesting season, and in good conditions, she can reproduce again and again over many years. Genetic work on Florida pythons has shown that a single clutch of eggs can have more than one father, which increases genetic mixing and can help the population adapt faster to new conditions. The hatchlings that emerge are not helpless. They are born already able to climb, swim, and kill small

prey. Put thousands of those young snakes into a landscape with plenty of food and almost no serious enemies, and the math begins to break away from anything people can manage. For a long time, the invasion did not look like an invasion. Early records of wild Burmese pythons in Florida go back to the 1970s. But for decades, they were treated as one-off oddities. A snake here, another one there, written off as escapees with no real future. Rangers and visitors still saw plenty of native mammals on

night drives along Everglades roads. Eyes flashed in headlights, and raccoons, apossums, and rabbits were common roadside shadows. The turning point came when scientists put those casual impressions into numbers. Researchers working in Everglades National Park compared road survey data from before the year 2000 with surveys from the 2003 to 2011 period after pythons had become well established. The difference was shocking. Records published in a major science journal showed that sightings of raccoons had

dropped by more than 99%, apossums by about 99% and bobcats by almost 88% in the areas where pythons were common. Marsh rabbits, which used to show up often in earlier surveys, simply disappeared from the later counts. In nearby areas where pythons had only recently arrived, those mammals were still seen more often, which pointed straight at the snakes as the main new pressure on the system. Follow-up work tracked marsh rabbits directly with radio collars. Those studies found that most tagged rabbits inside core python

territory were killed within a few months and the cause was very often a python. Taken together, the numbers told a clear story. The big snakes were not just another predator added to the food web. They had pushed whole groups of medium-sized mammals to the edge of local extinction in some parts of the park. When those mammals vanish, the effect does not stop with them. Small and medium mammals do more in a wetland than just run around and eat plants. They spread seeds, dig burrows that other animals use, and feed native

predators like bobcats, foxes, owls, and the endangered Florida panther. When a python eats those mammals first, it steals food from everything above them. Scientists worry about this not only for the sake of panthers and waiting birds, but also because of the way diseases move through a simpler animal community. One study on Everglades virus, a mosquito spread virus that normally moves between rodents and mosquitoes, found that when the mix of mammals in an area, changes, it can also change which

animals mosquitoes bite most. If snakes wipe out some hosts, but leave others, the mosquito community can shift toward rodents that carry certain viruses more strongly, raising the risk that those viruses spill over into people. While the mammals were crashing, the snakes were spreading. At first, almost all confirmed python records came from the core of Everglades National Park and nearby water conservation areas. Over time, reports and captures began to pop up farther east along canals deeper into

Big Cypress and down into the mangrove maze of the southern coast. Pythons were found in the Florida Keys and in wetlands stretching toward Lake Oichchobee. Maps that once showed a tight cluster of dots started to show a wide smear across the lower part of the peninsula. Each dot was only a snake that someone happened to see or catch. The real question was how many were out there beyond that thin layer of sightings. The answer turned out to be that nobody knew and that uncertainty was a problem on its own. Traditional

tools like visual searches and trapping work badly on an animal that is built to disappear. Studies of detection probability show that even skilled searchers miss most of the pythons that are actually present on a landscape. Federal scientists say there are still no precise agreed upon population totals for the greater Everglades because the probability of seeing a snake that is there is so low. One estimate often cited in recent years puts the statewide number somewhere between 100,000 and 300,000 animals. And some reports hint

that the real number could be even higher, possibly approaching half a million. To get a better handle on that hidden population, biologists began borrowing tools from genetics. One of the most important is something called environmental DNA or Edna. As snakes move through water, they shed tiny bits of skin, waste, and other cells. Those cells leave behind DNA that can be picked up in a simple bottle of canal or marsh water. In southern Florida, team started taking water samples from canals and marshes across the landscape and

testing them for python DNA. In many places where no snakes had ever been officially recorded, the water still carried clear python signals. that told managers that the invasion front was farther out than maps based only on visual sightings. In simple terms, the snakes were already there before anyone realized it. At the same time, genetic studies of the snakes themselves began to show how quickly they were adjusting to their new home. A harsh cold spell around 2010 killed many pythons that were caught out in the open during

freezing nights. Later work on python DNA found signs that the snakes that survived carried gene variants linked to nerve function and temperature tolerance. Those genes appear more often in the Florida population than in some source populations, which suggests that cold, hardier snakes were more likely to live through the freeze and pass their genes on. There is also evidence that the Florida pythons come from a mix of different original lines, including Burmese pythons and their close relatives, which may have boosted the

starting genetic diversity of the invasion. Once this picture came into focus, the next hard step was deciding how far people and science could really go to push the invasion back. the battle to take back the Everglades. Most of the fight against these invasive pythons happens far from any fire and mostly at night. Florida now pays a standing force of professional python hunters to walk levies, ride boats, and drive canal roads after dark. The state wildlife agency and the South Florida Water Management District both run

contractor programs that pay by the hour and by the snake. Since the early 2000s, more than 20,000 wild pythons have been reported removed through official channels, and thousands of those have come from these paid hunters. Some of the best known contractors have taken hundreds of snakes on their own. Many carcasses go to labs where scientists measure and dissect them. Others are tanned and turned into leather, a small way to pull a bit of value out of a problem that is costing far more than it

will ever return. Florida has also turned part of the response into a public event. Each summer, the Florida Python Challenge opens certain areas to registered members of the public for about 10 days. Anyone who wants to take part has to finish online training on snake biology, safe handling, and allowed areas, then buy a permit and head out. There are prizes for the most snakes removed and for the longest snake. In recent contests, hunters together have removed a few hundred pythons, and winners have brought in a

few dozen animals on their own. Those numbers will not erase the invasion, but the challenge keeps the problem in the news, trains more eyes to recognize pythons, and sends people into corners of the marsh that full-time crews do not always reach. Even with professionals and hobby hunters together, trying to spot a camouflaged snake over more than a million acres of wetland would be hopeless without better tools. One of the most effective tricks so far is to turn a few snakes into traitors. Groups

like the Conservancy of Southwest Florida catch large adult males, fit them with small radio transmitters, and release them again as scout snakes. During the breeding season, those males do what they were going to do anyway. They roam around looking for females. The human team follows the radio signal with antennas and receivers. When the male settles, the crew moves in, catches him again, and then searches for females that are coiled nearby. Some of those females carry more than 50 eggs at a time. Over years, this method has led to

the capture of hundreds of adults and has kept tens of thousands of eggs from ever hatching. From above, drones and other small aircraft are turning huge rough areas into something closer to a searchable map. After a burn, when the ground is black and open, teams can send small unmanned aircraft out over marsh and canal with thermal cameras on board. A warm snake against a cooler background shows up as a bright shape on the screen. One drone can scan many acres in a single flight and can reach muddy,

flooded ground that would take people hours of hard walking. On the ground, Florida has added noses to the search. The state and its partners now run python detection dog programs using animals trained to recognize the scent of python skin and musk along levies, trails, and road edges. Dogs like Truman and Elellaner have become minor local stars. Their handlers report that in thick cover, the dogs can find snakes that people walk past again and again, and that a trained dog can clear certain sights far faster than a line of people

with flashlights. Then there are the lures that sound like a joke until you watch them work. In one recent field test in the Everglades, researchers used fake rabbits that can give off heat and scent. These robot rabbits are set out in controlled pens or test plots. To a hungry python, a warm rabbit-shaped object that smells like prey is hard to ignore. When a snake moves in to investigate, waiting biologists can grab it and remove it. Early trials have been small, but they show that snakes will

approach these decoys, and the hope is to scale them up in certain hot spots where other methods have not worked well. Past all of these direct tools lies the uneasy subject of changing the snakes themselves. The genes inside an animal can be altered so that it has trouble reproducing, and that problem can spread through the population. A gene drive is one of the strongest versions of that idea. In a normal family tree, a parent passes a version of a gene to about half of its offspring. A gene drive is built so that

a chosen version is passed on to far more than half so it can spread quickly through a wild population. Right now, gene drives are being studied most seriously in insects like mosquitoes that spread malaria and in some small mammals. For large snakes, work is still stuck at the level of theory and lab talk. Science groups in the United States and overseas have warned that these tools come with serious risks. Once a gene designed to block reproduction is released into the wild, it would be very hard and maybe

impossible to call it back. There are worries that a change meant for one animal might move into a close relative or that it could spread across borders and affect wildlife in countries that never agreed to its use. Because of those concerns, major reviews have called for strong international rules and careful testing before any gene drive is ever used in open ecosystems. Thanks for watching. Now, check out the videos popping up on screen for more unbelievable stories.