Deployment of large teams of Micro Aerial Vehicles (MAVs) in real-world (outdoor and indoor) environments without precise external localisation or motion capture systems is very challenging. I will present the latest results of our endeavor towards fully autonomous compact flocks of MAVs with onboard artificial intelligence, which was achieved by the Multi-robot Systems group at the Czech Technical University in Prague together with Vijay Kumar Lab at the University of Pennsylvania. Stabilization, control, and motion planning techniques for steering swarms and formations of unmanned MAVs will be discussed in the talk. We shall focus on biologically inspired techniques that integrate swarming abilities of individual particles with a Model Predictive Control (MPC) methodology respecting the fast dynamics of unmanned quadrotors. Besides the basic principles of formation flying and swarm stabilization, examples of real-world applications of the introduced methods will be shown in complex indoor and outdoor experiments. First, we show how we use MAVs for indoor documentation of large historical objects (cathedrals) by formations of cooperating MAVs, where one MAV carries a camera and its neighbors carry light sources with the possibility to set a relative angle between the camera axis and the lights as required. Second, we demonstrate cooperative manipulation of large objects by a pair of MAVs developed for the international MBZIRC competition. Last, we present the fully autonomous flying robot Eagle.one hunting for unauthorized drones.