Walking kinetics of the stick insect using a low-inertia counter-balanced, pair of independent treadwheels

A treadwheel system consisting of two light foam wheels rotating independently on a counterbalanced gimbal is described. A stick insect rigidly fixed by the meso- and metathorax walks readily on the two wheels and can make turning movements in which the wheels rotate with different velocity. The dynamics and coordination of the animal on this device are compared with free walking, walks on heavier single wheels and walking on mercury.