*some* mealworms for commercial sale are chemically altered to prevent pupation... resulting in a prolonged larval stage and bigger worms...but this means no eventual beetles so no start to a worm farm. Additionally, not all growers feed "clean" and what goes into the worms goes into your birds. *i* would find a local source for starter stock (there are small and larger growers all over the place). If you arent sure where to look let me know.