I first encountered hair-chewing when volunteering in a child’s first grade classroom. One of my tutees could not begin any task without wrapping a strand of her hair around her fingers, then sticking it in her mouth. As time went on, I wondered why her mother didn’t just cut her hair really short.
There’s a revolting photo of what happens when this is carried to an extreme. Scroll down to the second story here, and put that sandwich down.