One of the gifts we received for Christmas was a big box of fungus-filled mud - a mushroom kit from River Valley Ranch in Wisconsin. Ours was to grow white button mushrooms. We had never tried this, and it was both fun and easy. The most enjoyable part of it was being able to actually grow and harvest something in the middle of winter. Mushrooms need no light to grow, so we set the box in our basement and followed the instructions. There are two plastic bags - the larger one at bottom, which contains the mycelium needed to grow the mushrooms, and a small bag containing the topsoil. You open the small topsoil bag and sprinkle it on top of the larger: Store it in a slightly warmer location until the Mycelium partially grows through the topsoil. (We put ours under a heat vent) Then move it to a cooler location, and that temperature change is what starts the mushrooms growing. And they grow... and grow... and grow, until I truly understood the meaning of...