Millipedes and Isopods depend on a good quality substrate for shelter and food. Josh's Frogs Milli Mix provides a source of hard woods, organic compost, leaves, and trace minerals that your inverts need to thrive. Milli Mix comes in a 2 quart bag that weighs 1 lb, and contains enough substrate for a small critter keeper or other similarly sized enclosure. <br> <br> <b>How to Use:</b> Place a 2-4" thick layer of Milli Mix in your invertebrate's enclosure. Depending on the species, add the desired amount of reverse osmosis or distilled water. Mist or add water regularly to provide adequate humidity. Replace when substrate becomes uniform (resembling garden soil) or eaten substrate (appears as small balls) makes up more than half the substrate.