After years at sea, salmon swim back to the exact stream where they hatched, sometimes hundreds or even thousands of kilometers inland. In the open ocean they appear to navigate by Earth's magnetic field; closer to shore, they follow the unique scent of their home stream, imprinted when they were young. Experiments that blocked their nostrils proved it.
In 2022, a young tagged bar-tailed godwit flew from Alaska to Tasmania in about 11 days of nonstop flight, covering 13,560 km without eating, drinking or landing. Before departure, these birds pile on huge fat reserves and shrink their digestive organs, which are useless during the journey.
To escape rivals, a dung beetle rolls its ball of dung in a straight line. At night, it holds its course using the glowing band of the Milky Way. In a planetarium, researchers showed that beetles rolled straight under a starry sky but wandered aimlessly when the galaxy was switched off. It was the first animal known to navigate this way.