Book III: River and Sea. Chapter 13, Journey to the Sea.
We meet a new named character in Chapter 13: an eel named Anguilla. Ten years old, she lives in Bittern Pond, but is soon to make her journey to the sea.
For the first time in her adult life, the food hunger was forgotten. In its place was a strange, new hunger, formless and ill-defined. (p. 121)
Carson masterfully describes animal instinct throughout Under the Sea-Wind. Later on the same page she writes:
But many times that night, as the wind and the rain tore at the surface film of the pond, Anguilla was drawn irresistibly toward the outlet over which the water was spilling on its journey to the sea.
How different are humans from the eel Anguilla? After college a strong restlessness led me to journey a thousand miles over land with no plan other than to leave my childhood home. I was determined to find a new home, to support myself and achieve independence: to become an adult. At the time I interpreted this strange drive as a divine call. But it was bodily instinct that I felt. It demanded I travel beyond my safe, small community to find my future.