This book is about the ways in which many animals form groups; for instance, schools of fish, flocks of birds, and swarms of insects. Covering both invertebrate and vertebrate species, the authors investigate three-dimensional animal aggregations from a variety of disciplines, from physics to mathematics to biology. The first section is devoted to the various methods, mainly optical and acoustic, used to collect three-dimensional data over time. The second section focuses on analytical methods used to quantify pattern, group kinetics, and interindividual interactions within the group. The section on behavioural ecology and evolution deals with the functions of aggregative behaviour from the point of view of an inherently selfish individual member. The final section uses models to elucidate how group dynamics at the individual level creates emergent pattern at the level of the group.