Converting “pony poop” in this vermicomposting bin has become a major part of our garden fertilty program. Each 4x8-foot bin has two sturdy 4x4 lids, made of ¾-inch plywood on 2x4 framing, stout enough for the heaviest use. Because each 4x8 bin has two lids, it can be managed as two separate sections (but with no partition between)—a key to our management practices.