Enlarge (credit: RamonCarretero/Getty)

A hammerhead shark less than one meter long swims frantically in a plastic container aboard a boat in the Sanquianga National Natural Park, off Colombia’s Pacific coast. It is a delicate female Sphyrna corona, the world’s smallest hammerhead species, and goes by the local name cornuda amarilla—yellow hammerhead—because of the color of its fins and the edges of its splendid curved head, which is full of sensors to perceive the movement of its prey.

Marine biologist Diego Cardeñosa of Florida International University, along with local fishermen, has just captured the shark and implanted it with an acoustic marker before quickly returning it to the murky waters. A series of receivers will help to track its movements for a year, to map the coordinates of its habitat—valuable information for its protection.

That hammerhead is far from the only shark species that keeps the Colombian biologist busy. Cardeñosa’s mission is to build scientific knowledge to support shark conservation, either by locating the areas where the creatures live or by identifying, with genetic tests, the species that are traded in the world’s main shark markets.

Enlarge (credit: Estradaanton/Getty Images)

You’re driving somewhere, eyes on the road, when you start to feel a tingling sensation in your lower abdomen. That extra-large Coke you drank an hour ago has made its way through your kidneys into your bladder. “Time to pull over,” you think, scanning for an exit ramp.

To most people, pulling into a highway rest stop is a profoundly mundane experience. But not to neuroscientist Rita Valentino, who has studied how the brain senses, interprets, and acts on the bladder’s signals. She’s fascinated by the brain’s ability to take in sensations from the bladder, combine them with signals from outside of the body, like the sights and sounds of the road, then use that information to act—in this scenario, to find a safe, socially appropriate place to pee. “To me, it’s really an example of one of the beautiful things that the brain does,” she says.

Scientists used to think that our bladders were ruled by a relatively straightforward reflex—an “on-off” switch between storing urine and letting it go. “Now we realize it’s much more complex than that,” says Valentino, now director of the division of neuroscience and behavior at the National Institute of Drug Abuse. An intricate network of brain regions that contribute to functions like decision-making, social interactions, and awareness of our body’s internal state, also called interoception, participates in making the call.

Enlarge / 2023 marked the first sighting of a yellow-legged hornet in the United States, sparking fears that it may spread and devastate honeybees as it has in parts of Europe. (credit: Miguel Riopa/AFP via Getty Images)

In early August 2023, a beekeeper near the port of Savannah, Georgia, noticed some odd activity around his hives. Something was hunting his honeybees. It was a flying insect bigger than a yellowjacket, mostly black with bright yellow legs. The creature would hover at the hive entrance, capture a honeybee in flight, and butcher it before darting off with the bee’s thorax, the meatiest bit.

“He’d only been keeping bees since March… but he knew enough to know that something wasn’t right with this thing,” says Lewis Bartlett, an evolutionary ecologist and honeybee expert at the University of Georgia, who helped to investigate. Bartlett had seen these honeybee hunters before, during his PhD studies in England a decade earlier. The dreaded yellow-legged hornet had arrived in North America.

With origins in Afghanistan, eastern China, and Indonesia, the yellow-legged hornet, Vespa velutina, has expanded during the last two decades into South Korea, Japan, and Europe. When the hornet invades new territory, it preys on honeybees, bumblebees, and other vulnerable insects. One yellow-legged hornet can kill up to dozens of honeybees in a single day. It can decimate colonies through intimidation by deterring honeybees from foraging. “They’re not to be messed with,” says honeybee researcher Gard Otis, professor emeritus at the University of Guelph in Canada.