Some things decompose readily; some things decompose slowly; some thing essentially decompose so slowly that they essentially don't decompose; a very few things are forever. Waxes decompose very slowly, which is why cuticles of fossil leaves persist so well for millions of years. Sporopollenin is the stuff that land plant spore and pollen walls are made of and it doesn't decompose at all. No organism has an enzyme that breaks these molecules down. Wonder if they've tried feeding pollen to meal worms? TPP asks this because humans have invented a few nasty things that do not decompose either, so they hang around and accumulate. Styrofoam and other polystyrenes being some of the more common ones. But say what? Mealworms can eat styrofoam and subsist on it? That's just amazing! A colleague of mine used to keep a colony going and hand out the mealworms (beetle larvae really) to visiting school kids as a snack because they are edible. The real funny part came when he'd turn to their teacher and say, "Your teacher will show you how to try new foods." Ha! They were worse than the kids. So now you can raise mealworms on styrofoam, one of the nastiest kinds of plastic pollutants, and then use the mealworms as a stir-fry ingredient, or chicken or fish food, or energy bars, or something. Where is my Man Eating Bugs cookbook? This is such a handy discovery.