How to Raise Mealworms at Home (The Simple Way)
Mealworms turned out to be one of the more unexpectedly useful things on our homestead. We've fed them to our chickens, toads, axolotls, and wild birds. They make excellent fishing bait.
They're quiet, low-maintenance, and take up almost no space. Once you understand a few basic principles, they practically take care of themselves.
Container and Substrate
You don't need a fancy setup. We use cat litter boxes from the Dollar Tree — shallow, affordable, and easy to clean. A single layer of mealworms across the bottom is all you're after. Crowding causes problems; spread them out.
For substrate, wheat bran is our go-to. It's lightweight, which keeps airflow good even when mealworms burrow into it. Dense substrates like cornmeal or oatmeal trap moisture, and moisture is your biggest enemy. Mold follows moisture, mites follow mold, and suddenly you have a real problem on your hands.
Before you use any substrate — even wheat bran you've purchased pre-treated — heat treat it yourself. Pour it into a baking pan with plenty of room to stir.
Set your oven to anywhere between 170°F and 220°F and leave it for around 20 minutes. The real goal is simply to get the bran evenly warm throughout. When you're ready to check, insert a probe thermometer halfway down — don't stir first, and don't let the probe touch the bottom of the pan.
You're looking for 150°F. According to research on stored grain pests, most insects and mites die within an hour at 122°F and within a minute above 144°F (Fields, P.G., Journal of Stored Product Research, 1992). Once your bran hits 150°F throughout, it's clean.
If you find cold spots, stir well and return the pan to the oven — with the oven off — to let the heat distribute evenly, then check again. Treating a large batch? Use multiple pans and fill every rack. Let everything cool completely before sealing it in a container for storage.
Even treated bran can pick up hitchhikers between the bag and your bin. This step is always worth doing.
Feeding
Mealworms get their moisture from food rather than a water dish. Root vegetables are our staple — sweet potato is a favorite here, but carrots and regular potatoes work well too.
We also feed the cores and stems left over from lettuce, cabbage, broccoli, and cauliflower. I think of these as "dry moisture" foods — they hold a good amount of water internally, but they don't seep into the substrate the way juicy produce does.
That distinction matters. You want your mealworms to draw moisture from their food without that moisture ever reaching your bran.
Whatever you feed, pull it out within 24 hours. Don't leave food scraps sitting in the bin.
Underfeed on purpose. This is the most important habit you can build. It's easy to add a little more next time if they've cleaned up what you gave them. It is very difficult to salvage a wet, moldy bin. When in doubt, give less.
The Life Cycle
Mealworms go through four stages: egg, larva, pupa, and beetle. Each stage has its own needs, and knowing what to expect at each one is what separates a thriving colony from a frustrating one.
We've written a full breakdown in our [Mealworm Life Cycle Guide] — including what to look for, what goes wrong, and how to fix it.
Short-Term Storage
If you want to keep purchased mealworms alive without running a full colony, the refrigerator is your friend. Put them in a ventilated container with substrate and slide them in. They go into stasis around 45–50°F and can hold that way for weeks at a time.
The key is a simple rhythm: two weeks in the fridge, one day out to warm up and feed, then back in. A carrot piece on top of the substrate is all they need on their day out.
Repeat that cycle, and you can keep mealworms alive and healthy for a couple of months with very little effort.
We raise and sell mealworms locally, along with wheat bran in 1 and 5-pound bags. If you'd like your mealworms gut-loaded — fed with our own calcium-dense recipe before pickup — just let us know when you reach out. We charge a small $1 upcharge for the extra prep time and ask for 72 hours to harvest and prepare your order.
Want to understand why mealworms are worth raising in the first place? Visit our [Why We Raise Mealworms] article. Ready to go deeper on the biology? Our [Mealworm Life Cycle Guide] has everything you need.