Mich. Comp. Laws § 117.5h

Sec. 5h. (1) Whether or not so provided in its charter, a city may, by ordinance, regulate or prohibit public nudity within city boundaries. (2) As used in this section, "public nudity" means knowingly or intentionally displaying in a public place, or for payment or promise of payment by any person including, but not limited to, payment or promise of payment of an admission fee, any individual's genitals or anus with less than a fully opaque covering, or a female individual's breast with less than a fully opaque covering of the nipple and areola. A mother's breastfeeding of her baby does not under any circumstances constitute nudity irrespective of whether or not the nipple is covered during or incidental to the feeding.