It’s peak cold and flu season, which means taking a lot of preventative measures. Frequent hand-washing is a must, as is avoiding co-workers or friends who are sick. But we humans are not the only animals that change behaviors to keep diseases at bay. So do ants.

“So there are the foragers (工蚁) and the nurses — it’s two different groups of work,” said Natha of the University of Lausanne. She and her colleagues observed ants to see their reaction to the presence of a disease.

“The nurses being made of young workers typically, stay inside the nest and take care of the eggs. And the foragers are all the workers spending most of time at outside of the nest to collect food and defend the territory.”

Forager ants are at greater risk of getting exposed to diseases because they leave the safety of the nest. So the researchers sprayed a common virus on a small group of forager ants and then followed their movements to see the way other ants reacted.

“We marked all ants in the colony with individual labels, which carries these two-dimensional bar code marks like QR code which is automatically detected and recorded using a tracking system.”

After the infection, the nurse and forager ants stayed within their working places and interacted less outside of their work group. The researchers also saw that forager ants spent more time outside of the nest. “They increase that amount by 15 percent, so by quite a large amount.”

Isolating behavior stops the spread of the virus. “Something that’s quite interesting in these ants that’s been shown by the study is that in their ability to avoid infecting other members of the community, ants may be more advanced than we are,” Natha said.

For the first time, researchers have used an animal’s own chemistry to grow electrodes (电极) inside the tissues of living fish, making the boundary between biology and machines difficult to distinguish.

The technique uses the body’s sugars to turn an injected gel into a flexible electrode without damaging tissues, experiments show. Zebrafish with these electrodes grown in their brains, hearts and tail fins showed no signs of ill effects, and electrodes tested in leeches (水蛭) successfully stimulated a nerve, researchers report in the Feb. 24 Science.

Someday, these electrodes could be useful for studying how biological systems work or improving human-machine interfaces. They also could be used in brain stimulation therapies for depression, Parkinson’s disease and other conditions.

Soft electronics aim to bridge the gap between soft, curvy biology and electronic hardware. But these electronics typically still must carry certain parts that can be easy to cracks and other issues that impact performance. And inserting these devices inevitably damages tissues, says Magnus Berggren, a materials scientist at Linköping University in Sweden.

Growing soft electronics inside tissues can have weaknesses too. External electrical or chemical signals that transform chemical soup into electrodes can cause damage. It’s possible to genetically modify cells to make enzymes that do the job. But Berggren and colleagues’ method gets results without genetic alterations.

The fish appeared to suffer no ill effects, and the team saw no evidence of tissue damage. In leeches, delivering a current to a nerve via a soft electrode induced muscle contractions.

“The approach utilizes elegant chemis try to overcome many of the technical challenges,” says biomedical engineer Christopher Bettinger of Carnegie Mellon University in Pittsburgh. But long-term performance is unclear. Substances in the body could reduce electrodes. “The team also needs to improve how precisely the electrodes stimulate nerves,” says chemical engineer Zhenan Bao of Stanford University. “The relative abundance of sugars in tissues dictates where electrodes form for now,” Berggren says. “Swapping a component in the material for elements that attach to specific bits of biology could make targeting more precise,” he says.

Wild animals are known to listen to each other for warnings that predators are near. Some birds, for example, flee when neighbors make a loud noise to announce a snake's presence.

The fairy wren is a small Australian songbird. It is not born knowing the "languages" of other birds. But recent research says it can learn the meaning of a few important sounds.

Andrew Radford is a biologist at the University of Bristol in England and co-writer of the new report published in early August in the journal Current Biology. He told the Associated Press, "We knew before that some animals can translate the meanings of other species' ‘foreign languages,' but we did not know how that ‘language learning' came about."

Birds have several ways of learning life skills. Some knowledge is genetically passed down by their parents and some comes from direct experience with the world. But Radford and other scientists are exploring a third kind of knowledge: information from fellows.

Radford and researchers at the Australian National University carried out the study in the country's National Botanic Gardens in Canberra.They attached to their bodies specially-designed, sound-producing equipment called "tweeter speakers." They wanted to see if fairy wrens would react to sounds of other birds even if they could not see them.

The scientists first played the birds two recorded sounds that they likely had never heard before. One was a warning cry of a thornbill, a bird not native to Australia. The other was a computer-generated bird sound called "buzz."

When the 16 fairy wrens in the study first heard the sounds, they had no special reaction. The scientists then tried to train half of the birds to recognize the thornbill's cry as a warning sound. They tried to train the other half to recognize the computer-generated "buzz" as a warning call.

After three days, the scientists tested what the birds had learned — and their students passed the test. The fairy wrens trained with the thornbill's cry, fled when they heard it. The group trained with the buzz, fled when they heard that sound. Neither group reacted to the sound taught to the other.