At least 3 days in advance: Make storks. Prepare cake base. Attach a cake board to bottom of craft block with icing and wrap with foil. Tint 8 oz. fondant blue, 8 oz. green, reserve 8 oz. white. Roll fondant 1/8 in. thick and cut4 x 16 in. blue runway strip and 6 x 16 in. grass strip. Brush backs with water and attach to cake base; smooth strips together. Attach white ribbon to base of craft block and icing decorations to ribbon with royal icing; let dry. To make baby conveyor belt, roll out and cut 4 x 3/4 in. strip of white fondant; let dry on waxed paper board covered with cornstarch. Keep prepared base away from light to prevent fading.
Trim off front and bottom of house cake to level. Attach house to cake base with icing. Ice smooth; spatula ice roof fluffy. Pipe tip 12 band eaves. Mark door and window areas with toothpick as follows: Front windows 3/4 x 1 1/2 in. high; door 1 3/4 x 3 1/2 in. high, side windows 1 1/4 x 1 1/2 in. high. Pipe in areas with tip 3; smooth with finger dipped in cornstarch. Outline doors and windows with tip 55; add tip 2 dots and message. Pipe tip 233 pull-out grass around house. Insert storks into cake. Using royal icing, cover legs with tip 5; pipe tip 3 outline feet. Pipe tip 3 center lines on runway.
Insert two 2 in. lengths of dowel rods into cake base for conveyor belt base, positioning at height of side window ledge. Position fondant conveyor belt. Tie babies with ribbon; position on conveyor belt and on beaks of storks.