While sleeping on a leaf by day, the glass frog pulls nearly 90% of its red blood cells out of circulation and packs them into its liver. Its body becomes two to three times more transparent. Such a dense pile of blood cells would cause deadly clots in you, so understanding how the frog avoids it interests medical researchers.
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.