Using its powerful beak, a lorikeet gently preens its mate's feathers; young cheetahs rest together in the shade; fireflies semaphore to each other across a darkened landscape and a mongoose deftly bites its prey to death. The study of animal behaviour is about all these things and more. It involves absolute stillness and violent activity, and all the noises and smells and changes of colour and shape that characterize animal life. Taking the organisation of behaviour within the individual animal as its core, this is a clear, concise and readable textbook introduction to the fascinating world of animal behaviour, investigating Tinbergen's questions of causation, evolution, development and function. It provides lucid accounts of all levels of behaviour from the nerve cell to that of the population. The broad biological approach of this new and re-written edition makes it an excellent choice for all students and teachers of animal behaviour and psychology.