text: This practice is called pica.  Other examples of pica include eating starch, dirt, and clay.  It is a big problem in children, those with developmental disorders, and pregnant women.  Right now nobody really understands why this is done, but there are risk factors, iron deficiency being one of them, but also othr mineral deficiencies.  There is also clearly a cultural aspect to this.  It is thought that people who suffer from pica tend to eat non-nutritive foods, becuase it is culturally acceptable, and it may be learned from someone else.\n\n\nYou can read more about pica here:\nhttp://www.emedicine.com/ped/topic1798.htm