I think China is a good reminder that the word "migrant" is just newspeak, most countries use it to refer to people fromother countries, China use it for people from another city...
本地 (ben di)- from local / basic soil. Often used as a badge of pride.
民工 (min gong)- common term for migrant worker in China. Interesting decomposition of the work - 民 (min) meaning a person, or member of the people. 工 (gong) meaning work (with one's hands, literal). This would be the closest match for a European moving country in seek of wage.
Also note that without a hukou they receive limited education and government services. This prevents them from settling in the cities they work in.
Religion? Ethnicity? Country of origin?