These experiments were performed with a team of nano quadrotors at the GRASP Lab, University of Pennsylvania. Vehicles developed by KMel Robotics. I strongly encourage you to watch the whole video as it gets increasingly impressive.
This was also interesting as these larger quadrotors seem to almost play like children with building blocks. In this video teams of quadrotors autonomously build tower-like cubic structures from modular parts. Work done by Quentin Lindsey, Daniel Mellinger, and Vijay Kumar at the GRASP Lab, University of Pennsylvania.