Raising mealworms are, in my opinion, the easiest of the worms to raise. They are also the favorite treat of my chickens and the wild birds, especially during baby season. Even my husband appreciates them come fishing season. So whether you like giving momma birds a break, have pets that depend on or enjoy them, or like to fish, mealworms can be useful to nearly everyone. Since they are sold at a premium, it makes sense to raise them, and doing so is extremely cheap and low maintenance.
Although you can start with mealworms purchased from a local store, we offer a Mealworm Starter Kit loaded with worms, beetles, pupae and eggs to get your mealworm colony producing months faster than starting with just worms. Our starter kits are available here.
What are mealworms, exactly? Mealworms are the larval stage of the Darkling beetle. The adult Darkling beetle lays many small, white eggs. 4-19 days later they will hatch into tiny mealworms. The mealworms grow over a period of time (based on food availability and temperature). Once full grown, they will become pupae. They remain in this state from 2 weeks to 9 months, finally hatching into white beetles. As the beetles age they change from white to brown to black. Once they become an adult, they will mate, lay eggs, and so on.
Mealworm (larva), pupa and adult Darkling Beetle
As a quick note, I prefer mealworms to Superworms, mostly because superworms bite and mealworms do not. There are some advantages to superworms, and they may be more appropriate to your needs.
If you look around online, you will find many systems including rotating breeding trays, nursery trays, etc. This method does work, and results in a higher yield. However for the average user, the simpler one bin method will work great, and with less work. Although it is a one bin system, I always recommend you have two bins of worms, and I make this recommendation for all worm varieties. This ensures you don’t lose everything in the event that something goes awry in one of the bins.
Here is what you will need:
- Plastic container or aquarium
- Drill or mesh & duct tape
- Wheat bran or cheap plain oatmeal
- Chicken feed (optional)
You can chose any plastic or glass container you prefer. The worms/beetles cannot crawl up smooth sides. The two important aspects of the container is that it is at least 4-5” deep (and the wider the better), and is well ventilated. You do not have to use a lid, but there is a risk of other creatures getting into your mealworms, like moths. I prefer to use stackable plastic drawers, like this. I do not add any lid or mesh to these, and they get enough air flow. Plastic filing boxes also work great. The bigger the container, the more worms you can raise.
If you use a container with a lid, you can either drill holes, or cut out the middle and replace it with mesh or window screen. I caution against drilling holes, as this does not seem to provide enough air flow and there is a high risk of mold which can be fatal to your worms. I speak from experience, unfortunately. This is where having two bins was helpful…
Next, take the container of your choosing and fill it with wheat bran or oatmeal. I use bran, which you should be able to find at your local feed store. Surface area is more important than depth, so it would be better to have 12”x12” of bran that is 4” deep, than 8”x 8” of bran that is 12” deep. Mealworms are not particularly picky however, so don’t stress too much about this. Just make sure you have at least a few inches of bran/oatmeal in the bin (any more than 8” is a waste), and there is a few inches from the bran to the top of the container.
Now that your container and lid (if using one) are ready to go, it is time to add the worms! You can buy them locally, try looking for them in fishing or reptile/pet stores. You can also purchase them from us here or get off to a quicker start with a Mealworm Starter Kit. Either way, I recommend you start with at least 500-1000 worms. The more you start with, the more you can use right away and the quicker the population will grow.
After you add the worms, place a few potato or carrot slices in the container. The mealworms and beetles use this for food and hydration. Don’t add too many because you don’t want mold in your container. Now it is time for the easy part! Just put the worms in a nice dark spot that’s about room temperature, and let them do their thing. I store mine in the closet or the water heater room in the garage.
Beetles on a new potato slice
Be sure to check your worms every week or two. Replace their potato or carrot pieces as needed. In a few weeks you should find that some of the mealworms have become larvae. This is good, as you are on your way to a bin that can start reproducing. You can use some mealworms at this time, but always remember not to use too many. If you use all the worms, there won’t be any left to turn into beetles. If there are no beetles, there will be no eggs, which means no worms.
When you finally have beetles, I have found it beneficial to add a sprinkling of chicken feed in the bin. The beetles will eat it up! This gives the beetles a variety of vitamins and minerals, and prevents them from eating eggs or young mealworms.
Depending on the size of your bin, eventually you will find that the wheat bran has been replaced with a dark sand like material. This is called frass, and simply put, is mealworm poop. A few times a year you will have to sift the worms and beetles out of the bin, throw out the frass, and refill the bin with wheat bran. Try not to do this more than necessary however, as you will also be throwing out small baby worms and eggs. I throw the frass in my chicken coop and let them scratch through and find any worms I’ve missed. I use a mesh strainer from the dollar store to sift them out.
You will also have to periodically remove the sheddings that accumulate on the top of the bin. I simply take the bin outside and wave the lid over the top, using the generated wind to blow them out.
Note the darker layer of frass on the bottom. You can see the transition from bran flakes on the top to the sand like frass on the bottom.
If you find mold in your bin, immediately open the top and let it air out. Sift out as many worms and beetles as you can, and throw out all of the bran. Before you add new bran to the container, clean it out with a diluted bleach water mix to destroy the mold spores. Rinse well and allow to dry. Finally, when you re add the bran and worms, try not to add any of the moldy bran that might be mixed in with the worms.
Mold is caused by either overfeeding, poor ventilation, or both. Either feed less or change to a different top to prevent it from happening again.
And that’s about it! If you have any questions or comments, feel free to comment below! As always, we thank you for reading!
Keywords: mealworm, mealworms, meal worm, mealworms, beetle, pupae, darkling, Tenebrio molitor, kit, farm, starter, colony, beginner, instruction, how to, raise, raising, what to feed, chicken, duck, poultry, gecko, lizard, reptile, make your own, DIY, do it yourself, breeding, bin, protein, tier, tower, care, fact, wheat bran, fertilizer