How does the author use metaphor in the memoir, There I Am: The Journey From Hopelessness to Healing?

As the author portrays them, red ants are both predatory and aggressive. She first encounters them while on a visit to her family when she is deep in her dependency on pain medications, and in the hopelessness associated with that dependency and other aspects of her life. The ants then become a point of metaphoric reference for the author as she describes both her dependency and her sense of hopelessness in terms that echo those associated with her descriptions of the ants.