Reviews Craving Earth by Sera L. Young Share this: Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print By Science News March 25, 2011 at 10:46 am Human biology and culture are interwoven in this exploration of pica, the craving to eat clay, dirt, starch and other nonfood substances. Columbia Univ. Press, 2011, 228 p., $29.50.