Bear

Bears lose almost no muscle during nearly six months of hibernation. Humans can shed 20–30% of muscle after two weeks of bed rest. A *Science* study found gut bacteria recycle waste urea into amino acids for muscle protein; NASA studies the idea for long spaceflight.

During World War II, the Polish army had a Bear soldier named Wojtek. Adopted in Iran, he helped carry artillery crates at the 1944 Battle of Monte Cassino, was promoted to corporal, and became his unit’s emblem as a bear holding a shell.

Pandas are bears that lost their umami receptors through evolution, leading them to eat bamboo instead of meat. However, their digestive systems remain carnivore-like, digesting only 17% of what they consume. To compensate, pandas spend about 14 hours a day eating.

The English word "bear" was originally a euphemism meaning "the brown one." Ancient people feared or revered the bear so much that they avoided its true name, and the substitute became permanent. The Russian медведь similarly derives from a euphemism meaning "honey eater."