  Search processes in the natural world are often punctuated by home returns
that reset the position of foraging animals, birds, and insects. Many
theoretical, numerical, and experimental studies have now demonstrated that
this strategy can drastically facilitate search, which could explain its
prevalence. To further facilitate search, foragers also work as a group:
modifying their surroundings in highly sophisticated ways e.g., by leaving
chemical scent trails that imprint the memory of previous excursions. Here, we
design a controlled experiment to show that the benefit coming from such
``environmental memory'' is significant even for a single, non-intelligent,
searcher that is limited to simple physical interactions with its surroundings.
To this end, we employ a self-propelled bristle robot that moves randomly
within an arena filled with obstacles that the robot can push around. To mimic
home returns, we reset the bristle robot's position at constant time intervals.
We show that trails created by the robot give rise to a form of environmental
memory that facilitates search by increasing the effective diffusion
coefficient. Numerical simulations, and theoretical estimates, designed to
capture the essential physics of the experiment support our conclusions and
indicate that these are not limited to the particular system studied herein.
