What does the opening sentence, "Nature is a battlefield." imply? Nature is a battlefield. You are either eating or being eaten. To survive, animals develop many ways to protect themselves from attackers. A hard shell is an excellent defense for slow-moving animals like turtles, snails, or clams. Some animals, like skunks, spray bad smells when threatened so that other animals will leave them alone. Certain animals try to fool their enemies by looking like something harmful. For example, some butterflies have big spots that resemble the eyes of an owl. The king snake, one of the most widespread snakes in the U.S.A., has red, yellow and black rings that look like the markings of a smaller but more dangerous coral snake. Other animals protect themselves by forming groups. Whether it's a pod of whales, a school of fish, or a pride of lions, living in groups helps animals defend each other against enemies and stay alive. Still other animals blend into their environment to become invisible. The Arctic hare, for instance, changes its coat color from brown in the summer to white in the winter, disappearing against the snow. These are just a few of the clever ways animals protect themselves in nature.