Also known as Morio worms and "superworms", they look like mealworms, but they are giant. Their nutritional value is poor, hence the importance of sprinkling them with multivitamins and calcium. They are noiseless, economical, have no unpleasant odor and require a little more space for housing than mealworms. Keep giant mealworms in a dry substrate such as oatmeal, chicken feed, cornmeal or a regular cereal.