Superworms are about 1.25-2 inches in length—because it is a natural product sizes may vary slightly. Superworms have long been a staple feeder insect in the reptile and amphibian hobby. Actually larvae of the darkling beetle Zophobas morio, superworms are inexpensive and easy to store before feeding them to your reptile or amphibian—simply keep them at room temperature and provide them with a food/water source, such as a carrot.