My worms live off : Peat Moss (soil medium), brown packing paper and paper bag strips (on top), powdered rock dust (on top), cannabis defoliation trim(on top), and organic bananna peels (buried in the soil.) I feed a fistful of food about once every 7-10 days and sprinkle/mist water every feeding. I have had them about 9 months and they have multiplied. I keep them in the veg room alongside my cloning tray. Even though I get fungus gnats in every pot every time I use new soil or compost anywhere in the room, I have never had gnats invade the worm bin. I believe it helps to A) keep the bin covered and B) keep the top tray of soil dry - I have 4 trays about 4 inches deep with mesh bottoms so the worms can crawl from tray to tray. The worms live in the bottom 3 trays.