What aspect of nature inspired the invention of Velcro?

The invention of Velcro was inspired by the way burrs cling to animal fur. Swiss engineer Georges de Mestral noticed that after a walk in the woods, burrs stuck to his dog’s fur and his own clothing. This observation led him to study the burrs under a microscope, revealing their hook-like structures, which he then replicated to create the hook-and-loop fastening system we know as Velcro.