This paper reports on an autonomous mobile robot embodying a simple instantiation of theDouble Hybrid Control Architecture, with a living animal in the control loop for improving robot navigational capabilities. In particular, a Carassius auratus (common Goldfish) receives a natural visual feedback from the environment, while its motor reactions, acquired by a digital camera and adequately processed, are mapped into motor commands, which are fed as inputs to the robot controller. Both the hardware and the software required for robot control is presented, as well as preliminary experimental data demonstrating the viability of the proposed approach.