Worm composting is an incredibly efficient way to convert kitchen scraps into nutrient-rich compost for your garden. But sorting out the undigested scraps can be messy and inconvenient. The Worm Factory automatically separates food scraps from finished compost. Simply fill the bottom tray with red wiggler worms, bedding and food scraps. As the worms finish digesting, they will migrate upward into the tray above, leaving rich castings behind.