A needle is a long, slender object with a pointed tip. Needles can be made from a variety of materials, including metal, wood, plastic and bone. Some needles are hollow and some are solid. The tips of needles can be of varying sharpness, depending on the application.
They come in several varieties relevant to body modification, including hypodermic needles, piercing needles, cannula needles, tattoo needles, and even knitting needles. Sewing needles on the other hand are not generally used in body modification except as a play item.