Symbols of turmoil and political mayhem are evident in Casca's use of animal imagery to describe the chaos that ensues in the natural world, “Men, all in fire, walk up and down the streets.And yesterday the bird of night did sit”. The strange behavior of the birds is an example of a disruption of the Great Chain of Being or the Natural Order as a direct result of Julius Ceaser trying to establish his own position on the Chain.
The Great Chain Of Being (heavily believed during Shakespearean times, circa 17th century) is a firm, pious hierarchical arrangement of all living things and matter, believed to have been created by God. The Chain starts from God and progresses downward to angels, demons, stars, moon, kings, princes, nobles, commoners, wild animals. It was believed that if the Chain was to be disrupted by the killing of an individual or when an individual attempts to create his own place on the Chain and defy God then all the beings below would fall into chaos, in this case the animals.
Animals acting out of order is evident in many other Shakespearean plays such as Macbeth; when King Duncan died the Old man stated “And Duncan’s horses—a thing most strange and certain—…'Tis said they eat each other.” This was a common belief held during the times of Shakespeare where many believed that the Great Chain of Being was a hierarchy decreed by God and if man attempted to alter God's will then mayhem and disaster would befall the natural world.