What's small, buzzes here and there and visits flowers? If you said bees or hummingbirds, you got it. You wouldn't be the first if you mixed the two up. Now a group of researchers even say we should embrace our history of considering the two together in the same group. The way scientists study bees could help them study hummingbird behavior, too.

    Scientists first compared the two back in the 1970s when studying how animals search for food. The idea is that animals use a kind of math to make choices in order to minimize the work it takes to earn maximum rewards. Researchers at the time focused on movement rules, like the order in which they visited flowers, and where flowers were located relative to others .It was “almost like an algorithm（算法）”for efficient searching, said David Pritchard, a biologist at the University of St. Andrews in Scotland. Hummingbirds and bees had similar solutions.

    As the field of animal cognition（认知）appeared, hummingbird and bee research parted. Neuroscientists and behavioral ecologists developed ways to study bee behavior in naturalistic settings. Hummingbird researchers compared hummingbirds to other birds and borrowed methods from psychology to study their ability to learn in the lab. To be fair, hummingbirds and bees differ. For example, hummingbirds have more advanced eyes and brains than bees. Honeybees and bumblebees are social; hummingbirds typically aren't.

    But however they perceive（感知）or process information, they both experience similar information, Dr. Pritchard said. In day-to-day searching for food, for example, hummingbirds may rely on more of a bee's-eye view than a bird's-eye view. Like other birds, they rely on landmarks, distances and directions to make maps when travelling long distances, but they don't use these cues to find flowers. Move a flower just an inch or so away from where a hummingbird thought it was and it will hover over the flower's original location. Dr. Pritchard is investigating if, like bees, hummingbirds engage in view matching — hovering, scanning snapshots of a place to its memory and using those as references later.

    One day an old woman was traveling alone in the mountains. Suddenly she saw something shining in the stream. When she came close, she found it was a precious （珍贵的） stone. She put the stone into her bag and went on with her trip.

    The next day the old woman met a young man, who was also a traveler in the mountains. The young man looked very hungry, so the old woman opened her bag to share her food. The hungry traveler saw the precious stone and asked carefully, “The stone is beautiful. Would you like to give it to me?”

    “Sure. Why not?” the woman said, and handed the stone to him.

    The young man left happily with the stone. He knew it was worth enough to give him security for a lifetime. But a few days later he came back to return the stone to the woman.

    “I've been thinking,” he said. “I know how valuable the stone is, but I give it back and hope that you can give me something even more precious. Give me what you have within your bag.”

    The woman opened her bag. It was almost empty. She looked at the young man and smiled, “I have nothing special in my bag, but I do have something precious — the joy of giving!”

    The young man felt ashamed and left silently.

    Winter is the perfect time to see Washington in a different light. The crowds have thinned, and those humid 95-degree days are long gone. And the National Zoo is a different experience because of 500,000 bulbs that illuminate the annual Zoo-lights celebration.

    Eco-friendly twinkly lights will decorate zoo walkways, trees and buildings. Sculptures featuring popular zoo residents, including elephants and giant pandas, light up in time to music.

    If walking and watching isn't enough excitement, head to Lion & Tiger Hill, home to a 150-foot-long snow-less tubing run. Rides on the trackless train and the carousel also will be available.

    Don't forget to visit a few of the zoo's real animals. The Kids' Farm, Reptile Discovery Center, Small Mammal House, Think Tank (orangutans) and Great Cats exhibit will be open in the evening. There's no guarantee, however, that the animals will be as lively as the humans in attendance.

    When: Friday to January 1 (except December 24-25), 5 to 9 p.m.

    Where: 3001 Connecticut Ave. NW, Washington, D.C.

    How much: Admission is free; limited parking is $22. Charges for tubing, train rides and carousel rides.

    For more information: A parent can visit nationalzoo.si.edu/events/zoolights.

    More ZooLights celebrations: For those outside of the D.C. area, here are some links to other zoos with similar events (not all are free):

    Columbus Zoo, Ohio: Through January 1.

    Detroit Zoo, Michigan: Through December 31.

    Denver Zoo, Colorado: December 2-January 1.

    Houston Zoo, Texas: Through January 15.

    You have probably heard of the Mozart effect. It's the idea that if children or even babies listen to music composed by Mozart, they will become more intelligent. A quick Internet search reveals plenty of products to assist you in the task. Whatever your age is there are CDs and books to help you taste the power of Mozart's music, but when it comes to scientific evidence that it can make you more clever, the picture is more mixed.

    The phrase "the Mozart effect" was made up in 1991, but it was a study described two years later in the journal Nature that sparked real media and public interest about the idea that listening to classical music somehow improves the brain. It is one of those ideas that sound reasonable. Mozart was undoubtedly a genius himself; his music is complex and there is a hope that if we listen to enough of it, we'll become more intelligent.

    The idea took off, with thousands of parents playing Mozart to their children, and in 1998 Zell Miller, the Governor of the state of Georgia in the US, even asked for money to be set aside in the state budget so that every newborn baby could be sent a CD of classical music. It was not just babies and children who were exposed to Mozart's music on purpose, even an Italian farmer proudly explained that the cows were played Mozart three times a day to help them produce better milk.

    I'll leave the debate on the impact on milk yield to farmers, but what about the evidence that listening to Mozart makes people more intelligent? More research was carried out but an analysis of sixteen different studies confirmed that listening to music does lead to a temporary improvement in the ability to handle shapes mentally, but the benefits are short-lived and it doesn't make us more intelligent.

    Right in front of the Minneapolis Central Library, a row of green hikes sits parked in a special stand. Each hike is designed with the logo "Nice Ride" the name of the city's bike-share program.

    Nice Ride bikes are a lot like the library books that people come here to borrow. To rent a bike, you simply use your membership card at a Nice Ride bike station. Members can rent one of 1, 200 bikes from 138 stations throughout Minnesota's largest city. People use the Nice Ridebikes to go to work, to go out on business, or just to enjoy the city's many bike paths.

    The rise of bike-share programs like Nice Ride is encouraging more people than ever to choose biking over driving. Skyrocketing gas prices and concerns about the environment have also gotten people to dust off their bike helmets, pump air into flat tires, and hit the road.

    Why ride? Not only is biking good exercise, but switching from a car to a bike also reduces the amount of pollution in the air. Carbon dioxide, a greenhouse gas linked to climate change, is one of the many polluting substances that come out of a car's tailpipe.

    Bike-share systems are found around the world in cities like London, Paris, Barcelona, and Melbourne, Australia. The largest program—with 70, 000 bikes—is in Wuhan, China.

    To make roads friendlier to non-motorists, the U. S. Department of Transportation has invested more than a billion dollars in cycling and pedestrian projects in recent years. The money went toward building thousands of miles of on-street bike lanes and bike-and pedestrian-only passages called greenways.