One cup (or more) of worms plus almost all of your vegetable and fruit scraps can go into the compost tube. Certain things will be difficult for the worms to eat and should be avoided. These include avocado pits, corn cobs, etc. The smaller the scraps that you use, the faster the worms will make vermicompost. DO NOT PUT ANY MEAT OR DAIRY PRODUCTS INTO THE COMPOST TUBE. For best performance, we recommend adding "bedding or bulking" materials along with kitchen scraps at a 1:2 ratio (1 part bedding : 2 parts kitchen scraps). This helps maintain compost air flow and drainage and prevents an excessive rate of decomposition by adjusting the nutrient balance. Popular bedding materials include torn/shredded cardboard, shredded paper, coconut coir, peat moss, and even handfuls of potting soil. Is this a system requirement? Nope, but it will aid in worm health and provide for better compost. Try not to "stuff" the compost tube -- you want to avoid compaction beyond what occurs naturally as the worms quickly minimize your kitchen scraps.