The topic of swarm robotics will be introduced, including the current state of the art and some current research platforms. The problems of scalability in robot swarms will be discussed, particularly of programming and maintaining a large group of robots. The Formica platform represents a novel, very low cost approach to swarm robotics. Its design and implementation will be described, and the lecture will culminate in a live demonstration of a swarm of 25 robots cooperating on a task.