The comparative investigation of the stick insect and cockroach models in the study of insect locomotion

Evolution has perfected very different six-legged walking machines from common neural and biomechanical components in an ancestral insect, as exemplified by the American cockroach and the stick insect. Comparative experimental investigations of both intact animals and reduced neural preparations, integrated with mathematical modeling, have been instrumental in advancing our understanding of insect locomotion. Locomotion in stick insects and cockroaches can be described by a related series of mathematical models that describe and quantify the effects of central coupling and feedback, and help explore the role of descending inputs (from higher neuronal centers) and neuromodulation. Insights into sensory–motor interactions and adaptive motor control in insects are useful in designing more responsive, robust, and adaptable bio-robots, which, in turn, can contribute to hypothesis-testing in biology.