Aquatic animals that live in water often leap out to catch prey in the air, while terrestrial and aerial animals dive into water to hunt aquatic animals. Some animals locomote on the water surface or lap water by repeated slamming and water-exiting motions. These dynamic interactions with the water-air interface have similarities in engineering, where water entry and exit problems play crucial roles in an object crossing the interface in industrial and physical systems. This review examines the physics of water entry and exit in biological systems through fluid mechanics principles originally developed for engineering applications. By identifying common governing forces, we aim to establish connections between biological strategies and engineering solutions, potentially leading innovations in bio-inspired technology.