From BEAM Robotics Wiki
Biology is the study of life and living things. This includes examining their structures, functions, and how they interact with each other and with their environments.
BEAMers look to biology for inspiration and ideas. This does not necessarily mean that a BEAMer must or will try to duplicate every aspect of the biological model that he or she is inpsired by. It simply means that usable aspects of that model are can be adapted and incorporated into the design of a robot.