Raising mealworms has been increasing in popularity over the last few years. Whether you plan to use them for your chickens, reptiles, hedgehogs or yourself, raising mealworms is easy and fun!
We raise mealworms for our chickens and Starter Kits in a tiered system. Although you could use a single bin, a tiered system has many advantages. The yield is MUCH higher, the worms are larger healthier, and harvesting is simpler.
Tiered systems can be made out of any plastic drawer, such as these Sterilite drawers or these drawer organizers (which I prefer and use), and works best when using at least 6 drawers. You'll need at least 3 drawers, and can use up to 20 drawers or more if you needed. Mealworms and beetles do not like the light, so if possible, purchase solid colors or black drawers. You can always cover the drawers with tape or spray paint for plastic if needed (don't paint the inside!), or place the colony in a dark location.
To start your mealworm colony, purchase a Starter Kits, such as the ones we sell in our store. You will also need Wheat Bran, window screen material or 1/8" (#8) hardware cloth, oatmeal and carrots (preferably organic), and your 3+ drawer container.
To set up your tiered system, you'll start by carefully cutting out the bottom of one of the drawers, and replacing it with the window screen material or hardware cloth. Fill this with 1-2" of oatmeal and add a carrot, and place at the top of the tiers. The beetles will eat the oatmeal and use the carrot for hydration. This will become the Beetle Bin. When you receive your starter kit, place the beetles in this drawer. The beetles will burrow to the bottom of the oatmeal to lay their eggs. The eggs will fall through the screen into the Worm Tray 1 below. This prevents the beetles from eating their eggs.
The second tray in your system, below the Beetle Bin, is Worm Tray 1. All Worm Trays need to have 2-4" of wheat bran and carrots. The worms will eat the wheat bran and use the carrot for hydration. As noted, this collects the eggs as they pass through the mesh in the Beetle Bin.
Below Worm Tray 1 is the Pupae Tray. All pupae are placed in here. No substrate is needed in this tray. When the pupae become beetles, hand separate the beetles and move them to the Beetle Bin.
After the Pupae Tray would be extra Worm Trays. If you are only using a total of 3 drawers, this would not apply. For those using 4+ drawers, fill your additional Worm Trays with 2-4" of wheat bran and carrots. These trays should be rotated with the Worm Tray 1 position. The more trays you have, the more often you will be able to harvest. Worms take 3-4 months to be full grown after hatching. So, if you are using a 6 drawer system and have 4 Worm Trays, each drawer should be rotated every 3 months (12 months a year/ 4 trays= 3 months). This means that every 3 months, you will harvest mealworms.
If you had an 18 Worm Tray system you would rotate drawers every 3 weeks, (52 weeks a year/ 18 trays = Appx 3 weeks), and you would harvest full grown worms every 3 weeks.
The easiest way to harvest worms is to use a sifter or sieve to separate them from the bran. You can also just pick them out by hand.
Below is an infographic to help explain the tiered system-
Tips & Tricks-
- Beetles and worms cannot bite, beetles cannot fly. If you don’t want to touch them, you can use a spoon.
- Tiered system reduces or eliminates cannibalism, which significantly increases mealworm yield
- Use dark colored trays or place bin in a dark area. Worms do not like the light. If this is not possible, it is ok to use what you can.
- Worms thrive in temperatures of appx 68-80 degrees F and 50-70% humidity. If too cold, their cycles slow or stop.
- As the beetles die, you can leave them in the Beetle Bin. They will eventually break down. We keep dermestid beetles in our mealworm colonies to help break down dead beetles, worms, and bacteria. We have much healthier colonies since adding them!
- It is easier to sift worms from bran than oatmeal
- Oatmeal will not fall through Beetle Bin mesh bottom, and should be used instead of bran
- Store harvested mealworms in the fridge until ready to use. This keeps them from pupating.
- If using a 3 tray system, simply hand separate or sift out larger worms from Worm Tray 1 to be used
- Using 4 or more Worm Trays is ideal. If using 4 worm trays, rotate every 3 months. With this rotation you’ll only harvest every 3 months. If you use more trays and rotate more frequently, you’ll harvest more often
- Bake bran at 200 degrees F for 20 minutes before using to reduce chance of grain mites. Allow to cool before using.
- Do not allow bran to become wet or moldy. If moisture becomes a problem, use smaller pieces of carrot or potato and feed more once the previous is consumed.
- Optional- Save old bran/frass in a spare container and see if any baby worms are inside. Feed with a potato or carrot for 1-2 months. Hand separate or sift baby worms. If none, frass makes an excellent houseplant or garden fertilizer!
If you would prefer to raise your mealworms in a single bin, please see this post.
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