Generally, the term "rod puppet" refers to a category of puppet which is manipulated from below with rods. Usually a central rod supports the head, while two smaller rods control the arms. In some cases, the central rod can be concealed by the puppet's costume. Often, the torso and arms are not fixed to the central rod supporting the head, enabling the head to move independently from the body. In other variations, the torso and arms of the puppet are fixed, like the head, to the central rod. When the puppet is not a humanoid figure, a series of rods may replace the central rod - as with a snake, for example. The term "rod puppet" can also imply any use of rods to animate the puppet, whether the puppet is controlled from below, from above (e.g., for the rod marionette, for which some authors use the term "rod puppet"), or on the same plane (e.g., with the bunraku-style puppet, which some authors also classify as a rod puppet). Strings are sometimes added to the rod puppet. When these are pulled, they allow the puppeteer to articulate other parts of the body, such as mouth, eyes and legs.