Dr. Sera Young is a faculty member in the Division of Nutritional Sciences at Cornell University and Reproductive Infectious Disease Fellow at UCSF. Her book is Craving Earth: Understanding Pica-- the Urge to Eat Clay, Starch, Ice and Chalk. Pregnant women usually engage in Pica, or those with nutritional deficiencies. Read more from the NIH. Dr. Young mentions the engaged group of people who eat ice (a type of Pica), and who like a certain type of ice made at Sonic Burger.