Hours after chowing down on an ear or two of buttery corn on the cob, you glance down in the toilet bowl and think, “I swear I chewed that.” Many of us have found ourselves in similar situations; the fact that corn kernels appear unchanged by their journey through our bodies is one of humanity’s open secrets.

According to The Takeout, the phenomenon isn’t specific to humans—cows experience it, too. This is somewhat surprising, since cows are ruminant animals whose digestive systems can break down tough materials better than ours can. When cows swallow their food, it softens in a special digestive chamber called a rumen and then gets sent back up for another round of mastication. (This also explains why it seems like cows are always munching on something.) But scientists have discovered that corn sometimes manages to emerge partially unscathed from this process of “chewing the cud.”

Not entirely unscathed, though. As University of Nebraska-Lincoln ruminant nutritionist Andrea Watson told Live Science, it’s only the thin yellow exterior of each kernel that escapes digestion. This is made of cellulose, a durable fiber that helps shield corn from bad weather, pests, and other potential damage. Humans can’t break down cellulose, but cows usually do a pretty good job—a testament to corn’s resilience.

Watson explained that about 10 percent of each kernel comprises cellulose, so whatever corn you detect in your poop isn’t quite as whole as you might think. The other 90 percent—a combination of starch, antioxidants, and other nutritional elements—does get digested. And if you’re consuming corn in a different form, like tortilla chips or popcorn, you can rest assured that the cellulose has already been processed enough that you won’t see evidence of your snack later.

[h/t The Takeout]