This road map of the U.S. created by a slime mold actually has real-world applications, Popular Science reports. In searching for food, the slime mold Physarum polycephalum settles on the most efficient path to food sources. You can model the most efficient routes between cities by creating an agar gel map with food sources for cities, and letting the slime mold do its work (there’s video at the link). “Because slime mold finds the paths that are most resilient to faults or damage, it could be used to make mobile-communication and transportation networks hardier.” Via MAPS-L.