Carbon dioxide is a climate-warming greenhouse gas. Trees are renowned for capturing it as they grow. But through microbes in their bark, trees soak up other major climate gases, too,…

Dozens of millennia-old Arabian cheetahs lie frozen in time. Researchers uncovered the ancient skeletons and mummies in Middle Eastern caves. No wild cheetah has roamed this region for decades. But…

In the Pokémon world, Pikachu is a chubby yellow mouse. It may look cute and harmless — but don’t be fooled. When its red cheeks start sparking and it whips…

Symptom (noun, “SIMP-tum”) A symptom is a clue that something is wrong. In medicine and psychology, a symptom is an effect of an illness or condition that a person feels.…