  Experiments have shown that surfactant introduced to a liquid-filled maze can
find the solution path. We reveal how the maze-solving dynamics arise from
interactions between the added surfactant and endogenous surfactant present at
the liquid surface. We simulate the dynamics using a nonlinear model solved
with a discrete mimetic scheme on a graph. Endogenous surfactant transforms
local spreading into a non-local problem with an omniscient view of the maze
geometry, key to the maze-solving dynamics. Our results offer insight into
surfactant-driven transport in complex networks such as lung airways.
