When invasive predators grow this large, they can alter entire food webs.

University of Florida researchers documented a surprising new threat to Burmese python eggs in the Everglades, adding to growing evidence that native wildlife is fighting back against the invasive species.

What began as a family outing to help remove invasive snakes from Florida's Everglades quickly turned into a terrifying fight for survival. Carl Jackson believed he had spotted a Burmese python measuring about 12 feet as it crossed a dirt road in Big Cypress National Preserve.

Florida researchers fitted GPS-collared opossums to track Burmese pythons from the inside — and the hidden biology of this tiny marsupial makes it the perfect secret weapon.