Walking animals can deal with large range of difficult terrain and can use their legs for other purposes as sensing or object manipulation. This is possible although the underlying control system is based on neurons which are considered to be quite sloppy and slow computational elements. Important aspects of this control system are error tolerance and the capability of self-organization. This chapter concentrates on insect walking behaviour. Apart from some references to relevant morphology it addresses behavioural investigations which are paralleled by software simulations to allow a better understanding of the underlying principles. Furthermore, hints to neurophysiology and to hardware simulations are given. Characteristic properties of the control system are its decentralized architecture that relies heavily on internal feedback as well as on sensory feedback, and that exploits the physics of the body.