Pica is an eating disorder characterized by an appetite for non-food items. It is most common in children and pregnant women, and can be caused by nutritional deficiencies like iron lack or mental disorders. Common non-food items eaten include ice, sand, paper, and dirt. While some items like ice pose little harm, others like dirt or sand can cause poisoning, damage to organs, or disease. Pica should be prevented to avoid health risks and treated by addressing any underlying causes.