Ever wonder how penguins stay ice-proof? Researchers have discovered microscopic structures in the feathers of Humboldt penguins that keep them from icing up—and that could lead to similarly ice-resistant materials. Humboldt penguins, which live on rocky beaches on the west coast of South America, swim in below-freezing waters that flow north from the Antarctic Ocean. And yet, their feathers rarely get icy. To find the penguin’s antifrosting secrets, researchers examined pieces of the feathers through an electron scanning microscope. They found that the penguin’s feathers are full of tiny, micrometer-scale interlocking barbs, they report this month in The Journal of Physical Chemistry C. This creates a dense net of fibers that water can’t penetrate—and it also traps air bubbles that prevent heat transfer, keeping water from freezing on the feather’s surface. But looking on an even smaller scale, researchers found tiny wrinkles on the surface of these barbs. These spaces also trap pockets of air, which decrease the amount of contact area between the feather and droplet. This makes water droplets less attracted to the feather’s surface. Inspired by these structures, researchers created a membrane of tiny overlapping nanofibers with similar deicing powers, which may pave the way for uniquely ice-resistant materials.