Distributing objects to layers for tweened animation

To separate layers to apply tweened animation to the objects, distribute selected objects in a frame. Flash distributes each object to a new, separate layer. Any objects that you don’t select (including objects in other frames) are preserved in their original positions.

You can apply the Distribute To Layers command to any type of element on the Stage, including graphic objects, instances, bitmaps, video clips, and broken-apart text blocks.