There are two ways to copy animation layers. You can copy an animation layer to create a duplicate layer with the same objects and attributes, or you can copy a layer to create a duplicate with the same objects, attributes, and animation.
To copy an animation layer with its animation
A duplicate layer that contains the same objects, attributes, and animation is created and placed below the selected layer in the stack.
To copy an animation layer without its animation
A duplicate layer that contains the same objects and attributes (but no animation) is created and placed below the selected layer in the stack.