This is the first book in the Santa Fe Institute Studies in the Sciences of complexity since Oxford took over the publishing of this series from Addison-Wesley. This book presents a unique combination of biology and computer science (including artificial intelligence, robotics, operations research, information display, and computer graphics), modelling the mechanisms underlying collective behaviour in social insects. Swarm intelligence is a new and rapidly developing subfield of artificial intelligence, and this book will be one of the central documents of this emerging subfield. The book should apeal to a broadly interdisciplinary audience of modellers, engineers, neuroscientists, and computer scientists, as well as some biologists and ecologists.