Meanwhile, another tool-using bird, the New Caledonian crow (Corvus moneduloides), has exhibited a different characteristic that we humans once thought was ours alone: the so-called "right-hand bias." Some 90 percent of humans are right-handed, and many scientists have long thought this was tied to our use of language. That's because our language circuitry is centered in the part of the brain that controls the right side of our bodies. According to Gavin Hunt of the University of Auckland, New Zealand, the crow also favors its right side when fashioning tools from leaves, which, like the woodpecker finch, it uses to get at bugs. After studying bill marks left on leaf material, researchers determined that the crow uses its right eye and the right side of its beak to carefully taper the gadgets. Hunt therefore suspects that the right-hand bias must be linked not to something specific, like language, but to something general, like the ability to carry out complex sequential tasks. He's also proven that you don't need hands to have a right-hand bias.