Mich. Comp. Laws § 289.4101

Sec. 4101. (1) Except as provided in sections 4102 and 4105, a person shall not operate a food establishment unless licensed by the department as a food establishment. (2) Separate areas for food service or preparation located in 1 building and actively operated under 1 management are considered to be 1 food establishment and only 1 license is required. The director may require separate licenses for these areas if managed separately even though under the same owner. (3) Except as otherwise provided in this act, a city, county, or other local unit of government shall not adopt or enforce licensing ordinances or regulations for persons regulated under this act.