Articles/sites that describe what a migrant farm worker is:

Invisible Children: A Portrait of Migrant Education in the United States

Migrant farmworkers, a fixture in American agriculture for many decades, are traditionally poor, hardworking people who travel great distances to live and work among strangers. Despite their instrumental role in agriculture, reliable statistical data accurately describing this population and their children are virtually nonexistent.

Migrant Workers' Children

Migrant life through the eyes of the child. Includes three students real life accounts of being a child of a migrant worker. There is also an interview with a students father and a survey.