Festo’s eMotionButterflies, bionic and autonomous, participate in collective behavior and can likely be used for, among other things, the prettiest surveillance ever. From the company website: 

Ten cameras installed in the room record the butterflies using their infrared markers. The cameras transmit the position data to a central master computer, which coordinates the butterflies from outside. The intelligent networking system creates a guidance and monitoring system, which could be used in the networked factory of the future.•