Biomimetics. That's the field dedicated to imitating aspects of nature to better understand, and potentially solve, complex human issues. It's the reason why so many engineers and researchers are creating robot models of animals.
Robotic animals can help researchers better understand locomotion, evolution, and simply how certain animals accomplish the amazingly unique tasks that they do. But they can also have tangible applications, from scouting for danger for the marines to aiding in search and rescue missions.