To navigate in an unknown environment, many natural species appear to rely primarily on motion information. Accordingly, the visual system of insects, arguably one of the simplest, is geared towards the detection of motion, which is implemented in mechanisms present at an early stage of visual processing. The interpretation of motion information may then produce percepts which are useful to navigation, such as the warning of an impending collision and the estimation of the distance to potential obstacles through egomotion. The original objective of the badge project was to demonstrate the feasibility of copying motion perception mechanisms onto a mixed mode analog/digital VLSI device. The initial success of the project led to other devices being designed with a view to improving the performance and stability of the analog circuitry. In retrospect, the original concepts appear to remain the most robust, which suggests that the most effective approach would consist of focusing on the simple but fundamental characteristics, and is supported by electrophysiological evidence.