What does Mama mean when she makes the analogy about people and scarecrows?

In The Bean Trees, Mama's analogy about people and scarecrows reflects back to the main theme of the novel. One of the principle messages of the novel, seen in Taylor's adoption of the Cherokee baby to her friendships with various women such as Lou Ann Ruiz, is that people can't succeed without or even survive without the human touch of compassion and generosity from other people. Taylor Greer's journey from Kentucky to Arizona continually draws and reinforces the message that human empathy, that deep feeling of bonding and understanding, between people is inescapably necessary.