Mealworms are the larvae of a beetle which feeds on stored cereal, particularly when it goes damp and mouldy. You casn breed them easily; all you need is a large container with airholes or fine mesh to let them breathe. Fill it with bran, add mealworms, keep it somewhere that isn't too dry, and give them time. Occasionally you need to sieve the contents out and add more bran, but the fine stuff at the bottom will contain masses of mealworm eggs so put it in a second container, add some bran, leave till they reach a reasonable size, then sieve it again and sling the bran mixed with mealworms back into the first container. You can produce masses that way, quite easily.
