Earthworms move through soil by a peristaltic wave of muscle contraction through a series of fluid-filled body segments. Sequential contraction and expansion of these segments results in the worm’s locomotion both above ground and within soil. Here, an earthworm-inspired soft robot is prototyped. The prototype consists of three polyethylene segments, which are inflated and deflated in a sequence that mimics the earthworm’s peristalsis. The current prototype is able to move through tubes of varied dimensions, and is an early step toward developing a soft robot that can explore buried environments. This may be especially applicable to archaeology, which often strives to explore such settings with minimal damage to a site. An earthworm-inspired robotic probe could provide information where currently used methods (such as geophysical sensing, excavation, and rigid soil probes) are ineffective.