This objective of this work was to leverage resonant structures coupled with primarily reactive actuators to achieve highly efficient legged locomotion. Specifically, the investigation pursued an alternative approach to the design of small-scale legged mobile robots, the essence of which was to incorporate a lightly damped skeletal structures that generate locomotion when vibrationally excited at a skeletal resonance by piezoelectric actuators. Directional control, and in some cases alternate gaits, were generated by designing different limbs to have varying resonant frequencies, then variable controlling the amplitude of motion of each limb by (slightly) shifting the excitation frequency. Experiments indicated that the elastodynamic robots had a specific resistance (a measure of locomotive efficiency) of approximately four. For purposes of comparison, a similarly sized robot actuated with DC motors was constructed. Experiments on the DC motor actuated robot indicated a specific resistance of approximately ten. The piezoelectrically actuated elastodynamic robot therefore demonstrated a locomotive efficiency approximately 2.5 times better than the DC motor and gearhead approach.