https://www.wired.com/2013/04/animal-superpowers/

Though true invisibility remains the stuff of comics, many creatures have evolved the ability to sneak up on their prey with eerily silent stealth. Among the best known are owls, which can swoop down on field mice with nary a sound fluttering from their wings. Though no one knows exactly how the special shape of their wings and feathers eliminate aerodynamic noise, scientists are studying the ability to better mitigate loud aircraft sounds. Another aerial predator, the Western Barbastelle bat, has also figured out how to remain invisible to the moths it eats: the creatures whisper their echolocation to avoid detection. The species’ echolocation pinging is 10 to 100 times lower in amplitude than their bat-cousins, preventing prey from being alerted to their presence. Underwater, the scariest thing to encounter (if you’re a tiny plankton) is the North American comb jelly. While these squishy ctenophores don’t seem formidable, they voraciously chow down on zooplankton. The comb jelly (below) uses tiny hairs inside its mouth to generate a gentle current that makes it hydrodynamically invisible to zooplankton, which remain completely oblivious until they are devoured.