Migrant woman like sleepwalker simile
The writer portrays a woman living in a squatters' camp for a long time. She is living in filth, lost some children, the children she gave birth to at the camp all died at birth or some time after birth. The writer describes her as having a glazed look like a sleepwalker. The woman is not herself anymore; she isn't living her life only living in misery.
Workers like animals simile
The writer describes workers at a large ranch where they are treated below any human decency. They aren't allowed to relax and any attempt to try to organize some sort of a human lifestyle is quickly and violently shut down. The writer describes the workers being herded about like animals.
Dust bowl metaphor
The writer describes the American migrant workers as those coming from a dust bowl. Faced with the same fate of drought, all of them are now in the same situation of desperately looking for work in order to survive so they are, so to say, in the same bowl.