Have a seat on this sturdy stool. It looks like a normal piece of furniture. Would you believe that it’s actually made of mushrooms?

Here’s how an Upstate New York company called Ecovative makes mushroom furniture. First, the furniture makers gather and clean leftover plant stems and stalks from farms. Then they introduce the stems to the little threads, or roots, of mushrooms. This network of roots is called mycelium (pronounced my-SEE-lee-um). Mycelium sees the small pieces of farm waste as food. It chomps, chomps, and chomps, forming lots more tiny white threads as it does. Soon the fibers coat every piece of waste.

The waste still seems a long way from becoming a footstool. But really, the process doesn’t take long at all. The furniture makers place the mycelium-coated waste into a board-shaped mold. The mycelium grows through and around the particles of waste. In just a few days, the material inside has filled the mold. It has also hardened into something useful: a board. The furniture-makers use the boards to make stools. They also build chairs, tables, and desks. "It's like growing a tree in the shape of your furniture," says Ecovative co-founder Gavin McIntyre. "But rather than a tree, we're using mushrooms."

The furniture makers admire their work. But they aren’t quite done. They don’t want mushrooms suddenly growing out of your footstool! So they dry the furniture. Now your sturdy stool will last—until you leave it out in the rain to decompose.