Each of the counties may enact and enforce ordinances regulating the presence of children in public places and on public streets and roads during certain hours at night.

Upon each of the counties enacting an ordinance pertaining to curfew for children, then so far as that county is concerned, the ordinance shall have full force and effect, and shall supersede sections 577-16, 577-18, 577-19 and 577-20 until the ordinance is repealed or otherwise made invalid.