Enlarge / An interdisciplinary team of roboticists, engineers and biologists modeled the mechanics of the mantis shrimp’s punch and built a robot that mimics the movement. (credit: Second Bay Studios and Roy Caldwell/Harvard SEAS)

The mantis shrimp boasts one of the most powerful, ultrafast punches in nature—it's on par with the force generated by a .22 caliber bullet. This makes the creature an attractive object of study for scientists eager to learn more about the relevant biomechanics. Among other uses, it could lead to small robots capable of equally fast, powerful movements. Now a team of Harvard University researchers have come up with a new biomechanical model for the mantis shrimp's mighty appendage, and they built a tiny robot to mimic that movement, according to a recent paper published in the Proceedings of the National Academy of Sciences (PNAS).

“We are fascinated by so many remarkable behaviors we see in nature, in particular when these behaviors meet or exceed what can be achieved by human-made devices,” said senior author Robert Wood, a roboticist at Harvard University's John A. Paulson School of Engineering and Applied Sciences (SEAS). “The speed and force of mantis shrimp strikes, for example, are a consequence of a complex underlying mechanism. By constructing a robotic model of a mantis shrimp striking appendage, we are able to study these mechanisms in unprecedented detail.”

Wood's research group made headlines several years ago when they constructed RoboBee , a tiny robot capable of partially untethered flight. The ultimate goal of that initiative is to build a swarm of tiny interconnected robots capable of sustained untethered flight—a significant technological challenge, given the insect-sized scale, which changes the various forces at play. In 2019, Wood's group announced their achievement of the lightest insect-scale robot so far to have achieved sustained, untethered flight—an improved version called the RoboBee X-Wing. (Kenny Breuer, writing in Nature, described it as a "a tour de force of system design and engineering.")

Enlarge / Coronavirus has swept through mink farms in Europe. (credit: Getty | Viktor Drachev )

The pandemic coronavirus has made its way onto two mink farms in Utah, leading to “unusually large numbers” of dead animals, according to a Tuesday announcement by the US Department of Agriculture.

These are the first reported cases of the coronavirus, SARS-CoV-2, infecting mink in the country. For months, authorities in European countries, including the Netherlands, Denmark, and Spain, have reported outbreaks in mink pelt farms, leading to the culling of more than a million of the soft, furry mammals. From laboratory experiments, it’s also clear that ferrets, a relative of minks, are also readily infected with the novel coronavirus.

The affected farms in Utah reported cases of COVID-19 in people working on the farms, who may have spread the infection to the animals.

Enlarge / Eyes painted on cattle rumps trick lions into thinking they have lost the element of surprise, a new study suggests. (credit: Ben Yexley )

Cattle herds in the Okavango delta region in Botswana are plagued by attacks by lions and other predators, prompting farmers to retaliate by killing the predators. An alternative nonlethal technique involves painting eyes on the butts of cattle to trick ambush predators like lions into thinking they've been spotted by their intended prey. It's called the " Eye-Cow Project ," and a recent paper published in the journal Communications Biology provides some solid empirical evidence for the practice. There are now practical guides for using the "eye-cow" technique available in both English and Setswana, so farmers can try it out for themselves.

Neil Jordan, a conservation biologist at the University of New South Wales in Australia, came up with the idea several years ago while he was doing field work in Botswana. Local farmers killed a pair of lionesses in retaliation for preying on their herds of cattle, and Jordan wanted to come up with a non-lethal alternative. The African lion population has dropped significantly from more than 100,000 in the 1990s to somewhere between 23,000 and 39,000 in 2016—much of it due to retaliation killings.

Jordan knew that butterfly wings sporting eye-like patterns are known to ward off preying birds, and are also found in certain fish, mollusks, amphibians and birds, although such patterns had not been observed in mammals. He also discovered that woodcutters in Indian forests have been known to wear masks on the backs of their heads to discourage any tigers hunting for prey. He had observed a lion stalking an impala, and noticed the predator gave up the chase when the prey spotted it. Lions are ambush hunters, Jordan reasoned, and decided to test his "detection hypothesis" that painting eyes on the butts of cows would discourage predatory behavior from the local lion population.

Enlarge / A vampire bat in flight with spread wings. The creatures build strong social bonds through grooming, sharing blood. (credit: Samuel Betkowski/Getty Images)

Vampire bats can starve to death if they don't feed for a mere three days, so strong social ties can be key to survival. For instance, a bat will sometimes share food with a hungry member of the same roost, regurgitating any blood it has consumed into the mouth of the hungry bat—a bit like a bloody French kiss. That's a true "friend." Evolutionary biologists have dubbed this behavior "reciprocal altruism." But vampire bats can also form bonds with strange bats from outside the roost, building up trust with mutual grooming first before moving on to food sharing, according to a new paper in Current Biology.

What's being tested here is a game theory model first proposed in 1998 colloquially known as "raise the stakes." It's similar to the famous prisoner's dilemma , in which two criminal suspects are arrested and separately offered a deal. If one of them confesses and the other doesn't, the defector will go free and the other suspect will get 20 years in jail. If both suspects confess, they will each get ten years in jail. The correct strategy, therefore, is to always confess, since one should assume the other party will act solely in his or her self-interest. Both players will reap the most benefit by cooperating with each other.

But cooperative behavior isn't always quite so simple as a binary choice between cooperating or defecting; it's more like a continuously variably investment. The "raise the stakes" model of relationships holds that two strangers can make low-risk, incremental investments to see if there is potential for further cooperation. If the other party reciprocates in kind, it builds trust and a relationship can form. If not, no relationship will develop, and nobody has spent too much time and energy on a worthless (from a survival standpoint) connection.