A bright yellow slime mold called Physarum polycephalum can do something that sounds impossible: it can solve mazes without having a brain, nerves, or even a single neuron.

In lab experiments, researchers placed food at different points in a maze. The slime mold spread out in many directions at first, then gradually pulled back from dead ends and reinforced the shortest route between the food sources.

It gets even weirder. Scientists have used this organism to model efficient transport networks. In one famous study, food flakes were arranged like cities around Tokyo, and the slime mold formed pathways that looked surprisingly similar to the region’s rail network.

It is not “thinking” like a human. Instead, it responds to chemical signals, food, light, and its own internal flow. But the result can look uncannily like problem-solving.

No brain. No map. Just goo doing geometry.