1. Do the grandparents have any rights to visitation?
Courts approach this issue differently. In general, unless the child is a dependent (http://divorceinfo.com/blog/?p=216), most judges would be reluctant to substitute their judgment for Mom's about her own parents, but you may get lucky.2. Could the grandparents file a case in court seeking custody (if facts show husband and wife are lousy parents)?
Yes. It would require a finding that the child is a dependent (and therefore in need of the court's protection).3. If such a case could be brought, would it be juvenile court or circuit court?
Juvenile court.