Velcro was invented by studying burrs stuck to dog fur

In 1941, Swiss engineer George de Mestral returned from a walk and noticed cocklebur seeds clinging to his dog's coat. Under a microscope he saw tiny hooks latching onto fabric loops — a system he spent eight years replicating in nylon to create Velcro. The name merges the French words 'velours' (velvet) and 'crochet' (hook).

Source: de Mestral, Swiss Patent 721,338 (1955); Biomimicry by Janine Benyus, HarperCollins (1997)