When I had my mealworms going, I filled a sweaterbox half full of unmedicated chicken feed. Added the mealworms, let the mealworms turn into beetles and start laying eggs for the next generations. I used potatos cut in half for moisture. You want to watch the potatos in the beginning because with not many worms, they can cause the feed to start to mold. However once the colony is going strong, the potatos won't last long enough to cause mold problems. You can pick up a 50lb bag of chicken feed real cheap at a feed store. Do not cover the sweaterbox because they can cause a lot of condensation build up once the colony takes off.