Mary Krupa became friends with the grey squirrels during her first week at Penn State, after spotting them running around and idly wondering what they would look like with tiny hats on their heads. Today, everyone at the university knows her as the "Squirrel Girl".

Mary started bringing them food, and gradually they began to trust her. She managed to put a hat on a squirrel and take a picture. Thinking that her colleagues could do with something to lift their spirits, she started posting similar photos on Facebook. The response was greatly positive, and before long Mary and her squirrels became an Internet sensation.

Growing up in a neighborhood outside of State College, Mary was always fond of birds and animals around her home, but she didn't interact with people very much. She was later diagnosed (诊断) with Asperger's syndrome, but the squirrels changed that. "The squirrels help me break the ice, because I'll be sitting here patting a squirrel and other people will come over and well just start like feeding the squirrels together and chatting about them," she said, "I am a lot more outgoing."

And in case you're wondering how Mary is able to get the squirrels to do what she wants for her photos, it has a lot to do with food. For example, whenever she wants them to hold or play with something, she puts peanut butter on the prop (道具), and they'll grab it. But getting to that part took a while. In the beginning, she would throw peanuts up the trees on campus and invite the squirrels to come down and get them, but they hesitated to approach her. She had the patience to earn their trust, though.

This year, Mary is graduating with a degree in English and wildlife sciences. She wants to be a science writer and educate people on how to preserve the environment. As for her furry friends, Mary plans to stay in the area and visit them as often as she can.

While Ellard Hunting and fellow researchers were out studying the weather at a field station in England, they noticed something unexpected on their instruments. Though there was no storm approaching, the scientists’ electric field monitors recorded a curious increase in atmospheric electric charge.

Nearby, honeybees that lived in on-site hives were swarming (蜂拥) as they attempted to find a new home. When the team took a closer look at their data, they discovered that the swarming honeybees had created an atmospheric electric charge. The researchers shared more details about their findings in the journal iScience.

“This is the first report of biology as a source of space charge.” says Hunting, a biophysicist at the University of Bristol in England. Scientists had known that individual bees carry a small charge while flying through the air, caused by the friction of their body parts against the air and each other. It’s similar to how rubbing a balloon on a piece of fabric creates static electricity. Scientists believe a bee’s charge helps pollen (花粉) stick to it and signals to other bees which flowers have already been visited. But until now, researchers had never recorded such a high voltage (电压) among swarming honeybees.

As far as electricity generation goes, a bee swarm’s charge isn’t so impressive: It would take about 50 billion bees to power an LED light. But compared to the charges produced by common weather events, the bees’ charge density was six times greater than an electrified (带电的) dust storm and eight times greater than a thunderstorm cloud.

Using the honeybee data, the researchers created a model to predict the potential atmospheric electric charge of other insects, including locusts (蝗虫), moths and butterflies. “Locusts swarm on biblical scales.” says Liam O’Reilly, a co-author and biologist at the University of Bristol. Clouds of these insects can span up to 1,200 square kilometres and contain roughly 30 million locusts per square kilometer. The researchers predict locusts would have a much bigger influence on the atmosphere compared to honeybees.

Scientists hope to continue exploring how biology influences physics and are curious to know if something similar is happening with other wildlife, such as birds and bats.

The Beagle Brigade

Return to the United States from a trip abroad ,and your luggage will get inspected by the Beagle Brigade, a team of beagles and their human partners. Working with human partners, the beagles sniff out potential threats to American agriculture.

An orange or apple, for example, might have a Mediterranean fruit fly. Hams could carry a disease such as hog cholera. These and other pests could destroy farmers' crops and livestock. " Once we introduce something     that     is not part of the environment, there may not be any controls of it in the environment," notes Lisa Davis at the National Dog Detector Training Center in Orlando, Florida. "The best thing for us to do is prevent it from coming across the border and becoming established. "

When a beagle sniffs specific food smells, it signals its partners by siting there. The human officer then investigates. When the dog is right ——which happens 90 percent of the time ——it gets an edible（ 可食用的） treat.

"The dog is not out there working," explains Davis. " It's out there playing. It's a game to the dog. "The handlers give the beagles plenty of food and love. They make sure they get first-class medical attention, too. When the dogs finally retire after 9 to 11 years ,they will find caring homes for them. It's a dog's life indeed!

Their people partners work and study somewhat harder. As specialized quarantine（检疫） officers,most hold degrees in the biological sciences or related sciences.

How well does the Beagle Brigade do its job? " On average," notes Davis, " each year our 54 teams prevent around 75,000 prohibited , restricted items. Since even one infected item could cause widespread destruction, that's a great result for America's agricultural environment.