  In the last 20 years, active matter has been a very successful research
field, bridging the fundamental physics of nonequilibrium thermodynamics with
applications in robotics, biology, and medicine. This field deals with active
particles, which, differently from passive Brownian particles, can harness
energy to generate complex motions and emerging behaviors. Most active-matter
experiments are performed with microscopic particles and require advanced
microfabrication and microscopy techniques. Here, we propose some macroscopic
experiments with active matter employing commercially available toy robots,
i.e., the Hexbugs. We demonstrate how they can be easily modified to perform
regular and chiral active Brownian motion. We also show that Hexbugs can
interact with passive objects present in their environment and, depending on
their shape, set them in motion and rotation. Furthermore, we show that, by
introducing obstacles in the environment, we can sort the robots based on their
motility and chirality. Finally, we demonstrate the emergence of Casimir-like
activity-induced attraction between planar objects in the presence of active
particles in the environment.
