Superworms are a delicious and nutritious food or treat for birds, reptiles and fish. They can be offered occasionally as a special treat to omnivorous reptiles and can also be fed to a range of insectivorous bird species. Superworms are a larger form of the traditional mealworm. Superworms are the larval stage of the darkling beetle and will feed on the oat bran provided in their tub. Additional bran, or vegetables such as carrot, may be added if necessary. This species can be stored in the refrigerator to prolong their longevity and postpone pupating.