This volume presents insights into the mathematics of movement with a focus on applications to animal ecology and cell biology. With the advances over the past decades in sensor technologies, from Global Positioning Systems (GPS) and radio-telemetry for the observation of moving animals to imaging technologies for tracking cells in live tissues, vast datasets on the movement and interactions of biological entities are providing exciting opportunities to answer many open questions. At the same time, the data revolution has brought novel challenges in the analysis of observational data with unprecedented resolution in space and time. To overcome these challenges, researchers have largely focused their efforts on specific systems or species, increasing the level of sophistication of the models in particular areas at the expense of the transferability of the know-how to the other disciplines. Commonalities between processes and models of the movement and interactions in animals in ecology, and cells in biology, do exist, but such inter-relations have rarely been considered, let alone exploited. This book explores these commonalities and identifies the fundamental differences that underlie a variety of phenomena in the two disciplines. By presenting the state-of-the-art quantitative methodologies and their application to the different types of processes, experiments and data that the applied disciplines bring, this book aims to catalyze the conceptual and technical integration of diverse movement models, and facilitate the emergence of radically new ways of mathematical thinking on complex challenges in animal ecology and cell biology.