Non-food Items?

The girls and I were at a health check-up recently when the nutritionist asked, "Do they ever crave any non-food items, like dirt and stuff like that?" I wasn't quite sure how to respond because although it sounded bad to say "Ya, they eat dirt sometimes," I thought the real question should be whose child hasn't eaten dirt before? I'd be more worried about a child who hasn't tried any "non-food items" than one who has. And not only dirt, but your pet's hairballs, crickets, leaves, seaweed, sand, cat food, soap, candles, magazines, books, toilet paper, etc. etc. We all remember "that boy" in preschool who ate bugs during recess, or the time you were so hungry at church, that you ate your kiwi flavored lip balm while no one was looking. I mean what exactly designates something as a non-food item when it comes to kids? Better yet, how do you know whether the child CRAVES the item or just feels like sticking it in their mouth at the time? Sometimes the girls try to bite my toes, does that mean that they crave toe? I figured it wouldn't make sense to complicate the question, my kids are healthy and they do eat non-food items, sometimes on a daily basis. I simply responded, "occasionally," and we went about our day.