The present work proposes a solution for performing indoor flocking with micro air vehicles (MAVs) in a fully autonomous way, considering the motion of the robots in three dimensions. The main characteristics that are looked for in the behavior of the flock are: adaptability, scalability and robustness. In order to meet these goals, each agent is equipped with on-board sensors that allow it to navigate autonomously in the environment; specifically, the IMU provides information about the velocity and acceleration of the drone and about its pose, while an UWB antenna measures the relative distance from every other agent in the flock and broadcasts the information extracted by the IMU to the rest of the swarm.