On the highways the people moved like ants and searched for work, for food. And the anger began to ferment.

– John Steinbeck

The Grapes of Wrath, Chapter 21. The final words of the chapter contains a warning to the owners about how easily people’s hunger can turn into anger. That anger is now beginning to "ferment," Steinbeck writes. He also uses a simile to compare the migrants on the highways to ants scurrying for work and food.