For a lesson in euphoria, look no further than a house cat twined around a twig of silver vine. When offered a snipping of the plant, which contains chemicals similar to the ones found in catnip, most domesticated felines will purr, drool and smoosh their faces into its intoxicating leaves and stems, then zonk out in a state of catatonic bliss.

In 2018, scientists set out on an expedition to survey the habitat of an endangered bat species in the West African country of Guinea. One night, a trap turned up something unusual: a new species of bat with a fiery orange body strikingly juxtaposed with black wings.

Locomotion through the seas can be arduous. Water is more viscous than air, and so underwater creatures must overcome strong frictional resistance as they swim.

The war on sharks has been waged with shock and awe at times. When a shark bit or killed a swimmer, people within the past century might take out hundreds of the marine predators to quell the panic, like executing everyone in a police lineup in order to ensure justice was dispensed on the guilty party.

Pound for pound, spider silk is stronger than steel and tougher than Kevlar. But it doesn’t start out that way.

This year, roughly a quarter of the vast Pantanal wetland in Brazil, one of the most biodiverse places on Earth, has burned in wildfires worsened by climate change. What happens to a rich and unique biome when so much is destroyed?

The sun is beginning to perk up again.

People joke about asking horses, “Why the long face?” We should redirect this question to hammerhead sharks. Their famous head extensions, called cephalofoils, can measure 3 feet from eye to eye. And scientists are still trying to nail down exactly what purposes they serve.

From a distance, the dead leaf praying mantis resembles its namesake: brown, crispy and still. Inch a little closer and it looks the same. But go even closer — too close — and a transformation occurs. The mantis whirls around, spreads its black-patterned wings and puts its arms behind its head in a pose reminiscent of Edvard Munch’s “The Scream,” showing off shocking red undersides.

Put a dolphin’s front flipper in an X-ray machine, and you will see a surprise: an arc of humanlike finger bones. The same goes for a sea turtle, a seal, a manatee and a whale. All of these animals had four-legged ancestors that lived on land. As their various lineages adapted to life in the water, what had been multidigit limbs slowly transformed into flippers.

Trees do not pay taxes. Some seem to avoid death as well. Many of the world’s most ancient organisms are trees, including a 3,600-year-old cypress in Chile and a sacred fig in Sri Lanka that was planted in the third century B.C.