The collective behavior of animals has been traditionally studied through observation, quantitative models of behavior, and devices of low intelligence. Nowadays, the advancements in the field of robotics allow for closed-loop experiments that occur in real-time, and for artificial agents that intelligently and autonomously blend into hybrid groups of animals and robots (i.e., biohybrid groups). Such systems provide scientists with the opportunity to study the social interactions that govern collective behavior from within the group of animals, either by mimicking them or by introducing precise stimuli to elicit and study their response. In this work, we introduce an open source Biohybrid Observation and Interaction (BOBI) platform for small animals, which consists of 3 main components: 1) an experimental setup; 2) a wheeled mobile robot called LureBot; 3) their software. We demonstrate the software and hardware design aspects that make BOBI stand out compared to our previous system and similarly purposed systems. Finally, we demonstrate our methodologies and the new robot’s agility, by conducting a set of preliminary experiments with rummy-nose tetra (Hemigrammus rhodostomus) fish, where we study: 1) the response of one fish swimming with a biomimetic and a non-biomimetic lure; 2) the robot behavior when the robot interacts biomimetically and in closed loop with the wall alone, with 1 fish, and with 4 fish. The experiments show that fish strongly prefer biomimetic lures, and that the robot is consistently successful in engaging in social interactions with the fish.