Several flies, like Drosophila, are quite useful as model organisms and have been used in research for centuries. They have unraveled several mysteries in the areas of genetics, developmental and evolutionary biology, cancer biology, and more. Similarly, chironomid midge larvae have also been extensively used in cytogenetical studies. In addition, they are minor crop pests, are disease vectors and pathogen reservoirs, cause allergic reactions, possess stress tolerance, and are used for environmental monitoring. Sarcophagid flies not only are used in studies of polytene chromosomes but are also vectors of diseases. Besides these, several flies are helpful in solving death mysteries and are excellent tools for forensic investigations. Existing books on flies emphasize either their taxonomy and distributional records or their role as vectors affecting humans and livestock. Therefore, it was decided to publish a book exclusively devoted to flies, especially focusing on their role in science and forensics. FEATURES OF THIS BOOK Each chapter begins with point-wise learning objectives Contains conclusions at the end of each chapter Includes "Points to Remember" sections for easy review Student- and reader-friendly approach throughout The present book starts with a chapter on the introduction of flies, followed by chapters on Drosophila as a model organism, its species and mutants, its role in biological science, as a tool to study human regenerative diseases, cytogenetic and evolutionary biology studies, and its inversion polymorphism. The book continues with chapters on chironomids midges, exploring their diversity and their role as pathogen reservoirs and for environment impact assessment and monitoring. A chapter on sarcophagids highlights studies on polytene chromosomes, followed by a chapter on the role of flies in crime investigations. This book will be valuable to students of entomology, researchers, and professionals in applied life sciences, as well as those involved in policy planning. Additionally, students preparing for competitive examinations and the general public will also benefit from this comprehensive work.