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Pica is a symptom and behavior of many children and adults with autism, and
other developmental disabilities.  It's not a craving of unusual foods. With
some of these individuals, it appears to be developmental, in that they remain
in the stage of much younger people.  There are many forms of PICA, including
the cravings that some people have which indicate nutritional deficits.  I'm
also a special educator.  Michele