How to Keep Mealworms Living Longer

Check containers of mealworms before you buy them for dead larvae. Pet stores frequently stock mealworms for several weeks and many of the worms die. If there are many dead worms in the container, don't buy it. If your local pet store frequently sells containers of mostly dead mealworms, consider buying from an online supplier.

Store mealworms in the refrigerator, where they can remain in a dormant state for several weeks. The worms don't need much space and the small plastic containers in which they're normally sold are perfectly adequate. Provide the mealworms with dry oats, cereal or flour. This substrate enables them to move around and increases their likelihood of surviving to adulthood. Once a week, remove the mealworms from the refrigerator for 24 hours.

Give the mealworms a small piece of apple or watermelon while they're out of the refrigerator. This provides them with both moisture and nutrition. Remove the food from the container before placing the worms back in the refrigerator. Some pet stores also sell mealworm-feeder cubes. These won't rot and you can leave them in the worm container when you put the worms back in the refrigerator.

Remove dead mealworms from the container regularly. When the worms begin to develop into pupae, transfer them to a new container with fresh substrate. Mealworms that are developing into pupae develop a crunchy outer shell and may appear to have legs.