In chapter six, Kino, Juana and Coyotito were being stalked and hunted down like prey. Kino had decided that they should leave their home since their lives were in danger. He told his brother that he was going north to where he heard there were cities.
In describing their trek, Steinbeck constantly uses animal imagery to emphasise the fact that they had become prey and that their predators were not far behind.
During their journey, Kino takes a nap but has a bad dream. He awakes, as Steinbeck describes:
And then he moaned and sat up suddenly, his eyes wide and his nostrils flaring.
Kino has become animal-like, as illustrated by the phrase, 'flaring nostrils,' a term mostly associated with an animal in a heightened form of excitement, either ready to pounce or defend itself. Kino is keenly aware of their situation and, like an animal, is ready to fight off the predators.
The animal metaphor is extended later when Kino hears his pursuers approach.
He listened again, an animal light in his eyes. ...his lips snarled...
These descriptors emphasise how like an animal Kino has become. His senses have grown sharper and he is much more aware of his surroundings, just like animal prey would be when it is aware of predators. Both he and Juana assume animal characteristics in their attempt to evade their pursuers:
They trotted quickly through the tangle of the undergrowth.
And Kino ran for the high place, as nearly all animals do when they are pursued.
...leaped from ledge to ledge into the shallow caves.
...Kino crawled into the largest one...
...he climbed up the brush cliff beside the water, clawing and tearing at the ferns and wild grape as he went...
These images add to the tension and drama as the reader imagines the family being vulnerable and trapped. One feels their fear and anxiety as they are relentlessly pursued by two trackers and a man with a rifle.
Kino eventually realises that it would be impossible to escape their pursuers and that he has to act. He decides to attack the three men. Juana watches as he prepares his assault. Her eyes are, of course, wide with anxiety and fear. From her hiding place in the shallow cave...
She peered like an owl from the hole...
The simile accentuates the fact that their their humanity has been ignored. The men hunting them do not see them as human anymore. They have become mere objects who need to be removed so that the men's greed can be satisfied. The description of Kino's movements as he goes down to attack the men, further emphasises the fact that he, in order to survive and save his family, has to become like an animal - ferocious, with no conscience or remorse. He has to be instinctual like an animal for them to remain alive.
Kino edged like a slow lizard down the smooth rock shoulder.
He crouched and took great slow long breaths to calm himself.
It is tragically ironic, however, that even though Kino manages to kill all three men, he cannot not save Coyotito. He and Juana decide to go home and return the pearl from whence it came.