Brachycephalus pulex, a tiny frog from Brazilian forests, is one of the smallest vertebrates known: adult males average about 7 mm, small enough to sit on your little fingernail. At that size, its inner ear works poorly and its jumps end in clumsy landings. Researchers think it may be close to the minimum possible size for a vertebrate.
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.