"Snake!"

At hearing this word shouted out, the two biologists leaped out of the car and took off running towards two snakes, a pair of 10-foot (3 m) Burmese pythons lying on a levee to catch sun.

One biologist grabbed one of the creatures by the tail. "It made a sound like Darth Vader breathing and then its head swung around and I saw this white mouth flying through the air." said biologist Lori Oberhofer. Python's jaws can open 180 degrees, the gums are an obscene white, and the teeth are needle-sharp and long.

The biologist caught the snake behind its head, but the python didn't succumb. "They defecate on you, on purpose, hoping to make you reconsider what you're doing," said Oberhofer. Both snakes were bagged, trucked off to the Everglades Research Center, killed and their bodies were used to scientific research.

Python control in the Everglades is a painstaking, around-the-clock race against a voracious, foreign snake species that has established in these wild marshes and put native wildlife at risk.

Pythons' most victims are raccoons, possums, muskrats and native cotton rats but also birds such as the house wren, pied-billed grebe, white ibis and limpkin and the huge snakes can put on risk already endangered species like mangrove fox squirrel, the wood stork, Key Largo wood rat, and Eastern indigo snake. "The Everglades doesn't work by itself anymore," says Leon Howell, 58, who has been associated with the park for the last 21 years as a visitor, naturalist, fishing guide and, presently, park ranger. "This whole landscape has to be managed today: water, fire, exotics - you name it." Without control, "there'd be pythons all over the place."

Pythons began to appear in the late '90s. Pet owners release their huge, unwanted snakes in and around the park and making the public understand the danger of this irresponsible action is still difficult. This tropical natural paradise is the only place in North America where crocodiles, manatees, rainbow-colored tree snails, roseate spoonbills, ghost orchids and tall royal palms can be seen together.

But these wetlands have been so drained and abused by humans in the last 100 years that a population of pythons - if left uncontrolled - could destroy this fragile net of life within a generation. "We still have a chance, with the python's numbers being so limited, to do something. But if we let this go, we don't know how far the pythons will migrate, how much they will reproduce." said Oberhafer.

Observations made in Everglades showed that even alligators can not stop the pythons, and the snakes are even able to kill alligators. Last fall, the carcasses of a 13-foot python (4,3 m) and a 6-foot (2 m) alligator were found floating in a marsh, the gator's tail and hind legs protruding from the split-open gut of the python.

"Sometimes pythons swallow things they shouldn't" said biologist Skip Snow.
The giant snakes reach 26 feet (8.6 m) length and over 200 pounds (80 kg) in their native region in Southeast Asia. Pythons are not venomous but kill their victims by squeezing and swallow them whole. Once they pass 8-9 feet (2,5- 3m), they can kill a human being and the largest can even swallow an adult!

The pythons reached America through pet shops and flea markets and currently 22 of the 24 known python species are traded in the US. "Since 2000, slightly more than 1 million pythons have been imported by the United States for commercial sale; nearly half are shipped to Miami," the U.S. Fish & Wildlife Service says.

Python hatchlings cost as little as $20 at a flea market. "They're so darling when they're tiny," Oberhofer says. "Later, the big attraction at home is being able to watch your python kill something - like a rat - and gobble it whole in its tank."

But within a year, pythons fed steadily grows 6 to 8 feet (2-2,5 m) or bigger. At this stage, owners cannot get rid of them and unwilling to euthanize their beloved pets, many release the pythons into the wild, unaware of the ecological mayhem they provoke.

Some captured pythons were tagged with radio transmitters and released into the wild to track their movements, habitat use and breeding patterns - and to betray the locations of other pythons. Four "tagged" pythons had led to the capture of 12 others through October and three more pythons with transmitters have since been released.

154 pythons have been removed in and around the Everglades through the first 11 months of this year, up markedly from the 95 caught in all of 2005, 70 in 2004, and 23 in 2003. Is this due to a larger number of pythons or are the python detectives simply more effective at catching them?