Mealworms are larvae of the Tenebrio Molitor species. They are just over an inch in length and have a semi-hard shell. Mealworms are an excellent food source for lizards, frogs, turtles, snakes, sugar gliders, hedgehogs, birds, and other pets. They should be kept refrigerated in the cups they are shipped in. Our mealworms are shipped in bedding they can eat. However, it may help to take them out of your refrigerator every 2-3 weeks and give them an apple slice. This will help preserve their size and extend shelf life. Leave the container out for a day or two, remove any leftover apple slice, and refrigerate again.