Like many animals previously unknown on the North American continent, the Burmese python arrived through the pet trade. (Language purists might reasonably ask if it is fair to describe these snakes as invasive. It is not as if they barged in on their own. People created the problem.) At least two million constrictor snakes — boas, anacondas and pythons — are believed to have been imported since the 1970s, part of a lucrative market for exotic species. Miami is an important hub for this trafficking.

One issue with Burmese pythons is that people cavalierly bought them when they were maybe a foot long. In short order, those little fellows grew to eight feet, 12 feet, 16 feet. Talk about buyer’s remorse. Unable to deal with these giants, owners often dumped them wherever seemed feasible. One way or another, snakes in South Florida found their way to the Everglades. There, they multiplied, again and again. Recent estimates by the National Park Service put the numbers there as high as 100,000. Walter E. Meshaka Jr. was the supervisory curator for national parks in southern Florida from 1995 to 2000. Even back then, Mr. Meshaka told Retro Report, the question was whether the python population would explode. And, he said, “Lo and behold, it did.”

Quite possibly, some experts in the field suggest, the local wildlife has been slow to appreciate the menace. “It’s probably a safe assumption that things like raccoons and possums probably don’t associate snakes with being something that really is a major threat to them,” Michael E. Dorcas, a herpetologist at Davidson College in North Carolina, said in a 2012 interview with Yale Environment 360, an online publication of the Yale School of Forestry and Environmental Studies. “Because,” Mr. Dorcas continued, “there really hasn’t been a snake big enough to eat a raccoon living in Florida for about 18 million years.”

While the python is more of a direct threat to native birds and animals than to people, attacks on humans are not unknown. One of the more horrifying instances occurred in 2009 when a 2-year-old girl in northern Florida was strangled by a Burmese python that belonged to her mother’s boyfriend. This eight-foot snake, which was later found to have been severely malnourished, broke free, coiled itself around the girl and squeezed her to death. Both the mother and the boyfriend were held responsible — convicted of manslaughter and sentenced to 12 years in prison.

The authorities in Florida have tried getting the unwelcome reptile population under control, but to little avail. A couple of years ago, they organized a Python Challenge, a come-one, come-all snake hunt on state land near Everglades National Park. It put barely a dent in the python population; no more than a few dozen of them were captured. Pythons have shown themselves to be masters of stealth. In a rather glum assessment, the United States Fish and Wildlife Service said in a statement last month that “scientists have not found any way of eradicating invasive constrictor snakes once they become established in the wild.” Some experts say the best hope to kill these creatures en masse may be a deep and prolonged freeze in southern Florida. Of course, everyone would then worry about the devastating effect on the state’s citrus crop.