Meet the highest mouse on Earth
The yellow-rumped leaf-eared mouse might only be a tiny critter, but it can live in some dire conditions. (Marcial Quiroga-Carmona/)The peak of Llullaillaco, the world’s highest active volcano, stretches some 22,000 feet above sea level and is almost like another planet. The peak straddling Chile and Argentina is one of the driest places on earth, making it the perfect place for mummies to remain intact for thousands of years and not much else. Temperatures regularly drop below freezing, and vegetation is scarce. Very little can live up here, including humans—the highest people live at permanently is 16,700 feet, a good thousand feet below the elevation of the main Everest basecamp in Nepal.These elevations are not what you’d call a livable situation for pretty much anyone. That is unless you are a teensy weensy Phyllotis xanthopygus, the yellow-rumped leaf-eared mouse.In February, researchers discovered one of these tiny mountaineers scampering around the...