Thank you for your question. Mealworms are relatively easy to keep. Upon arrival place them in a refrigerator, set at 45°F, until ready for use. When you are ready to use them, remove the desired amount and leave at room temperature until they become active, roughly 24 hours before feeding to your animal.
If you plan to keep the mealworms for longer than two weeks, remove them from the refrigerator, and let them become active. Once they become active, place a slice of potato on the top of the bedding to provide moisture, and let them sit for 24 hours. Then, place them back in the refrigerator.