We all have our share of unusual cravings, but few are as startling as the wide range of materials consumed by people with the disorder pica, the repeated eating of largely non-nutritive substances like wood, soil or paint chips. The word pica derives from the medieval Latin name for magpie, a bird reputed to eat just about anything [source: T.E.C. Jr.].
Thanks to Greek and Latin, there's a name for every neurosis, and the many flavors of pica are no different. Xylophagia describes the consumption of paper, pencils, tree bark or other woody items. Chewing and eating glass is the habit of those with hyalophagia, and of course there's also urophagia (urine), coprophagia (feces), geophagia(dirt), autosarcophagy (eating bits of oneself) and, yes, anthropophagy (human flesh).
People with trichophagia chew and/or swallow their own hair, which can result in a dangerous trichobezoar (hairball) that blocks the intestines and requires surgery. In 2007, surgeons removed a 10-pound (4.5-kilogram) trichobezoar that had completely filled the stomach of an 18-year-old woman [sources: CNN; Grant and Odlaug].
Such compulsions are frequently associated with a psychological condition or learning disorder. The prevalence of pica varies from 4 to 26 percent among the institutionalized, and the condition can co-occur with Kleine-Levin syndrome, mental retardation and schizophrenia [source: WebMD]. But it also can crop up among otherwise healthy children and in men and women of all ages and cultures, sometimes in response to a dietary deficiency [sources: Gowda et al.].