They build a paper nest by chewing small amounts of wood from trees, reeds or garden fences and mix it with saliva to form a pulp which is added to the nest in thin strips.
But the story's visceral appeal presents a problem for those who contend that the novel's poetic language and resonant imagery are merely cloaking devices for what amounts to a thin, lurid storyline that would barely pass muster in a bottom-feeding pulp magazine.