Setting up a Mealworm Farm

In our previous chapter, the residents at Urban Farm OC (Real Hens of Orange County and the humans), agreed to restart a mealworm farm. Lady Human ordered 10,000 worms from Rainbow Mealworms

Wondering what an order of 10,000 worms looks like? The post office drops off a box labeled “Live Animals,” and if you listen carefully, you hear all sorts of scratching and creepy crawly noises before you open up the box. Inside, is a heavy bag full of the creepy crawlers.

mealworms mealworms

The mealworms are dusty, and many people are allergic to their dust and frass (poop), so make sure that you protect yourself with at least a dust mask (a respirator rated for dust and mold is better) prior to handling them. Lady Human was sexy in her get-up:


Lady Human recounts her thoughts and how she began setting up the mealworms in their new homes:

I first examined our old mealworm farm, neglected for at least 6-8 months or more in a dark corner of the garage when we set it aside to clean up the area it was in originally and to deal with pesky invasive ants. I had already assumed that the entire colony had perished, because at first glance, the entire surface was littered with tons of dead beetles and shed skin on top of all the frass. As I was closing the lid, I noticed some pulsing…this is a sign that there is life. I knew that any remaining worms would be hungry and thirsty, and probably kept going by feeding off the carcasses of the dead worms and beetles. So, to tease them out of hiding and to see how many worms were left, I put in lots of banana peel and squash. They were thirsty and almost immediately climbed on top and into the goodies!

mealworms  mealworms

Photos above: Left – old colony littered with dead beetles, shed skin, and no readily apparent sign of life; Right – about 5-10 minutes after offering some squash, the first mealworms emerged

Using the vegetables and fruit bits, I lured as many worms out of hiding as possible and set them aside to be integrated with the new worms once the set-up was complete. I fed the remaining carcasses to the chickens, and sprinkled the frass in the garden — make sure you wear a dust mask or respirator when you do this!

Setting Up the New Farm


  • Containers for the worms’ habitat. I tried to recycle and use containers I already have, but they were all too small for what I wanted. So I purchased 3 shallow 28 qt. storage bins ($5 each, 23″ L x 16″ W x 6″ H) for the new bigger and better worm farm.
  • Wheat bran for the worm bedding. How much you will need depends on your container. I fill each container with the wheat bran until the level is about 1/3 to 1/2 the height of the container. I buy wheat bran from the bulk bins ($0.99 per lb) of my local grocery store, or I buy them from Azure Standard. As an alternative, you can also used rolled oats.
  • Mealworms! Lots and lots of them!
  • Vegetable or fruit scraps – kale/ broccoli ribs, banana peel, apple cores, carrots, potato skins, beet tops, etc.

Preparing the Container

mealworms mealworms

mealworms mealworms

I started by drilling ventilation holes into the sides of the containers (photo top left). There’s really no hard and fast rule. Just what you feel is appropriate for your climate and how/ where you want to raise them. I went through the trouble of covering the ventilation holes with scrap fabric, using duct tape to hold them in place (photo top right). The reason I do it this way is because I want to minimize and control the entry points for ants in case they invade. This also prevents fruit flies and other unwanted critters from entering. FYI, ants can go through the tiny gaps under the lid regardless of what you do. Instead of drilling holes, some mealworm-keepers cut out a large section off the lid or sides of the containers and they suggest buying or finding fine-mesh fabric or window screen to over the large hole. Again, do it based on your personal preferences. Instead of buying new material, you can use lightweight gauzy fabric scraps like I did, or recycle the netted bags used for packaging from onion, avocado or other produce (photo bottom left).

Once you’re satisfied with the ventilation, add the wheat bran to fill the container about 1/3 to 1/2 full, add worms, then add veggie and fruit scraps (photo bottom right). I also throw in some toilet paper rolls and scrap paper so that the worms have a place under which to hide.

Maintaining the Mealworm Farm

Worm Maintenance

After setting up the worms, it’s important to find a nice shady spot for the mealworms. I keep mine outside in a semi-shaded area of the patio. Some people keep their worm farm in a shed, garage or some even keep indoors (um, not for me). While the garage would be a great place to keep the worms, it’s not convenient for me, since I also grow fodder on the patio, and the maintenance of both in the same area is just better for me. When it gets too hot, I cover the worms to shield them from any direct sun, or I temporarily move them into the laundry room until dusk. Heat will kill the worms, so keep this in mind when you are trying to find a place for them.


Once the bins are set up, I only check the worms about every 3-7 days. I check for development, to remove old veggie scraps and to add new scraps. The frequency at which I check depends on the weather.

Pretty soon, you will see lots of shed skin and maybe even some pupae! It gets pretty exciting once the worms start to pupate, because soon thereafter, beetles will emerge, mate, lay eggs, hatch into worms, and so forth.

Life Cycle of a Mealworm

When you order mealworms, I recommend that you get ones that are as full-grown as possible, because they will be closest to pupating (do not get “super” or giant worms, those are usually treated with growth hormones).

The mealworms are the larval form of the darkling beetle. They start out as a tiny egg, about the size of a period. When they hatch, the worms are so tiny that you probably won’t be able to see them at all, until they get to about 1/4″, especially since they’re about the same color as the wheat bran. As the worms grow, they go through several cycles of molting and shed their exoskeleton. The worms will then pupate and turn a white and off-white color in a C-shape. The pupae don’t move much and may even appear dead. However, if you touch it, it should wiggle. After pupating, the flightless beetles emerge. The beetles first look light brown, then darken to black over time. After they mate and lay eggs, they will die, and the life cycle begins again.


Photo above: The dust on the beetle and around the pupae are bits of wheat bran and frass.

Some mealworm farmers go through the trouble of separating the pupae and beetles. You can if you’d like. However, I go by the motto of “simple but effective” in this regard. I don’t want to spend tons of time separating them. I just keep them all in the same bin. The only picking I do is to pick out the dead carcasses of worms, pupae and beetles to feed to the chickens first. When there is a large population of the worms and beetles, I just scoop a cup or so to feed the chickens, regardless of their stage in life. The chickens are happy to eat any of it!

Keeping the Ants Away

In Southern California, we are plagued by very invasive non-native Argentine ants. They love to attack and invade the mealworms. They go after the veggies and the worms in the mealworm bins. Once they invade a colony, it’s very hard to get the ants out, and if you do, you will have tons of ants crawling all over you. It’s not a pleasant experience at all. Ask me how I know.

So this time, I constructed a simple shelving unit with PVC pipes. I upcycled pipes dug up from the old sprinkler system and simply just purchased the fittings.  It’s a little bit wobblier than I’d like and I will reinforce it later. For now, it works just fine to hold the mealworms and keep the ants away. As you can see in the photo below, I submerged the legs of the shelving unit in containers filled with water. This acts as a barrier and prevents ants from accessing the colony.



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