FANG SIGNS: Giant snakes are invading North America and could soon take over large swaths of U.S. wilderness, a new federal study warns. Burmese pythons, African rock pythons, boa constrictors and yellow anacondas pose a serious risk to the ecology of national parks, the U.S. Geological Survey warns in its report, while reticulated pythons and three other anaconda species pose a medium threat. The study was motivated by the recent discovery that invasive Burmese pythons and boa constrictors are not only widespread in the Florida Everglades, they're reproducing there. Those snakes are now competing with native alligators, crocodiles and panthers to be the ecosystem's apex predator, and if the same thing starts happening in other places, the results would be disastrous. "Native U.S. birds, mammals and reptiles in areas of potential invasion have never had to deal with huge predatory snakes before — individuals of the largest three species reach lengths of more than 20 feet and upward of 200 pounds," the USGS warns. The U.S. Fish and Wildlife Service is now considering whether to declare these snakes "injurious species," a designation that would prohibit importing them or selling them across state lines. (Sources: ScienceDaily, Los Angeles Times, Dot Earth

WARMING WARNING: An e-mail that had been buried by the Bush administration has resurfaced, showing that the EPA tried to warn Americans about the public-health dangers of greenhouse gas emissions nearly two years ago. The EPA released the e-mail on Tuesday, a message the agency originally sent to the White House on Dec. 5, 2007, but was never opened. The Bush administration and then-EPA Administrator Stephen Johnson decided not to release the e-mail or the attached 28-page document, aside from letting three senators review it in July 2008, the Washington Post reports. Under new Administrator Lisa Jackson, the EPA publicly declared greenhouse gases a danger to public health in April, but her administration was also outed for having buried a hastily written report from an EPA economist that questioned the recent public-health endangerment ruling. Unlike the censored 2007 e-mail, however, this year's censored report — which opponents of emissions regulations have heralded as proof of political maneuvering in the EPA — was written by a lone EPA economist known to be skeptical of climate science, not a team of EPA climate scientists trained to study such things. (Sources: Washington Post, LA Times, Associated Press, NY Times)

UNAPEELING: For some reason, 7-Eleven is worried its customers might not feel comfortable buying produce at a gas station. To make sure its aging bananas don't turn brown on store shelves, the nation's largest convenience-store chain is testing a project to individually wrap its bananas in plastic — an apparent slap in the face to Mother Nature's existing banana wrapper. 7-Eleven is testing the idea at 27 Dallas-area stores, and could expand to most of its 5,787 locations by early 2010 if it goes well. While it may sound wasteful and unnecessary, 7-Eleven says it's working to develop a biodegradable plastic wrapper, and argues that by extending the shelf life of its bananas, it will reduce its carbon footprint by making fewer shipments to stores. (Source: USA Today)

VROOM OR DOOM: Hear that? No? It could've been a hybrid. MNN transportation blogger Jim Motavalli writes for the front page of the NY Times today that hybrid cars' quiet rides are a growing danger to pedestrians, cyclists and other motorists — a recent study showed that people could hear a gas-powered car coming from 28 feet away, but didn't notice a hybrid's sounds until it was within seven feet. For decades, automakers sought to make cars quieter, since internal combustion engines aren't known for subtlety, but now they're faced with too much of a good thing. Rather than trying to make hybrid engines noisier, however, automakers are looking into offering a sort of next-gen novelty horn — designer car noises, akin to a cell phone's ringtone. Some hybrids would make synthetic noises automatically as they drive, while others would be driver-operated. "It should be a manually operated noisemaker, a button on the steering wheel triggering a recording of your choice," the vice president of a hybrid advocacy group tells Jim. "It could play 'In-a-Gadda-Da-Vida,' or anything you like." (Source: NY Times)

VIGILANTE AGRICULTURE: A group of farmers and business owners was arrested outside the headquarters of the U.S. Drug Enforcement Administration on Tuesday, as they were digging up part of the lawn to plant hemp seeds in a protest of federal law. Hemp is the soft, durable fiber produced from plants in the cannabis genus, which includes marijuana. Hemp itself isn't a drug and has no psychoactive properties, and while eight states currently allow hemp cultivation for commercial or research purposes, a federal ban trumps those state laws. Hemp is native to North America and grows wildly throughout the United States — Thomas Jefferson and George Washington famously grew it — but President Ronald Reagan began a campaign to eradicate so-called "ditchweed" in the '80s. A House bill introduced by Rep. Ron Paul, R-Texas, and Rep. Barney Frank, D-Mass., would let states create their own hemp policies. "We've got a billion-dollar industry we're sleeping on," said one farmer who was arrested at the protest. (Source: Huffington Post)

LIKE WATER FOR CHOCOLATE: Eating chocolate and drinking water can both help dull the effects of pain, according to a new University of Chicago study. Researchers put rats in a pen with a heat lamp below the floor, which caused them pain in their paws when switched on. The rats normally lift their feet up when the lamp is on to avoid the pain, but they're much slower to do so while eating or drinking. Previous studies have shown that eating sweets like chocolate may help reduce sensitivity to pain, but the researchers were shocked to find out that drinking sweetened or even unsweetened water apparently had the same numbing effect as eating a chocolate chip, suggesting that the phenomenon has nothing to do with calories. "Water has no calories, saccharine has no sugar, but both have the same effect as a chocolate chip," says neurobiologist Peggy Mason. "It's really shocking." While the food-as-painkiller effect may be adaptive in the wild, however, it's also helping make nervous, anxious or otherwise stressed people more likely to overeat. The fact that water can be subbed for chocolate is a positive sign, the researchers say. "Ingestion is a painkiller but we don't need the sugar," Mason says. "So replace the doctor's lollipop with a drink of water." (Source: e! Science News)

Russell McLendon

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Photo (python and alligator): USGS

Photo (7-Eleven sign): Paul Sakuma/AP

Photo (hemp plant): U.S. Fish and Wildlife Service

Photo (lab rat): U.S. Department of Energy

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.