(a) Persons to be served. The summons and a copy of the petition shall be served on:
(1) The child alleged to be a child in need of care by serving the guardian ad litem appointed for the child;
(2) the parents or parent having legal custody or who may be ordered to pay child support by the court;
(3) the person with whom the child is residing; and
(4) any other person designated by the county or district attorney.
(b) A copy of the petition and notice of hearing shall be mailed by first class mail to the child's grandparents with whom the child does not reside.