In nature, dominance hierarchy is a fact of life. Animals live in groups, and within each group, one member is dominant while the others are submissive, and it is in the best interest of the submissives to understand their role quickly. Those who are subordinate express submissive behaviors by looking away and lowering head, body or tail. Extreme submission is marked by crouching down, rolling over and exposing the abdomen. To establish dominance, elk, for example, butt heads with rivals, and some species of African fish turn bright colors.
Most species have defense mechanisms to protect themselves against a dominant species or predator.
A horned lizard confronts its enemy by inflating its rear end to create the illusion of greater size, and if that doesn't work, it squirts blood from its eyes into the face of the attacker. Cuttlefish spray an inky fluid, creating an opaque screen blocking them from view long enough to escape. The Torpedo electric ray can deliver a shock of up to 200 volts for about a second. He never knew what hit him. He didn't have time to run and hide, and when it was clear he was in trouble, he tried puffing himself up, throwing up a smoke screen or two and running to the protection of the chatterboxes he called his friends.