Mar 17, 2020 - 05:41 AM
They do not need bedding while refrigerated (they are dormant and not eating), but it does help prevent cold bursts and condensation from harming them in older refrigerators.
Although you can put them straight into the refrigerator when you receive them, they will last much longer in dormancy if given a meal first. The ideal temperature for mealworms in the fridge is between 45 and 50°, but they will survive down to 42 degrees which is considered a safe temperature by the FDA for food as well.
To give them a pre-dormancy meal, feed them a grain (wheat bran, oatmeal, cornmeal, masa) and for water give them sliced carrots or potatoes. Let them eat for at least 4 hours to give them energy to store and they will last 6 to 8 weeks dormant in your refrigerator. Remove the vegetables, but keep the grain in the bin for storage.
The warmest spot in your fridge is the best for them, it is usually the shelf farthest away from the area designated for milk storage (for most people this is the top shelf).
You can remove any remaining worms once a month to let them eat for another 4 hours so they will last longer in the fridge by restoring their reserves for the dormancy.