Argo is more difficult to find because there are fewer customers who want it. (Starch eating, one form of pica, is dangerous because the eater replaces nutritious foods with starch AND a one pound box of starch is about 3500 calories. The body reacts to the cornstarch much in the same way as it does to corn syrup. It experiences a carb rush and then a craving for more. Not really different than chugging sodas or quarts of sweet tea, is it?)
Mice and certain insects are attracted to starched items. Starch is food.