In order to insure compliance with this chapter, all areas of licensed adult cabarets, adult motion picture theaters and adult drive-in theaters which are open to members of the public shall be open to inspection by City agents and employees during the hours when the premises are open for business. The purpose of such inspections shall be to determine if the licensed premises are operated in accordance with the requirements of this chapter. It is hereby expressly declared that unannounced inspections are necessary to insure compliance with this chapter.