This textbook on Animal Behaviour has been designed to serve as a comprehensive guide for B.Sc. students, with a specific focus on aligning with the latest National Education Policy (NEP-2020) syllabi of Guwahati University, Dibrugarh University, Assam University and Bodoland University. As an essential subject in the field of life sciences, animal behaviour is a captivating and integral aspect of biology that enhances our understanding of the interactions between animals and their environments. The primary objective of this book is to provide students with a deep and thorough understanding of the various facets of animal behaviour, including instinct, learning, communication, mating systems, and social structures. By exploring the diverse ways in which animals interact with each other and their surroundings, this text not only imparts fundamental knowledge but also nurtures critical thinking and analytical skills.