Contrary to popular belief, chameleons don't change color primarily to blend into the background. Their shifts mostly signal mood to rivals and mates and help regulate body temperature. The mechanism is physical: skin cells hold a lattice of guanine nanocrystals, and by adjusting the spacing between them, the chameleon changes which colors are reflected.
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.