Instructions on Breeding Mealworms

Breeding and raising live mealworms is a simple process, but it is time-consuming and requires regular attention and care. Raising mealworms to have a consistent supply year-round saves a great deal of money versus purchasing multiple times per year from a local feed store or an online retailer. You are also more likely to have higher yield when the worms are homegrown.

Listed below are instructions on raising, breeding, and maintaining a colony of mealworms. You can purchase a Mealworm Breeder Kit that includes everything you need to kickstart your colony. If all goes well, you should have mealworms to use as feeders within about 3 months.

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What You’ll Need

• 150+ Live Mealworms (we recommend 500+)

• Breeder Box – approximately 14" x 8" x 5”

• Mealworm Keeper (or any meal bedding)

• Mealworm Chow & raw vegetables (for food)

• Thirsty Cricket (and/or raw vegetables to provide moisture)

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Starting Your Colony

Step 1: Obtain Your Mealworms

• You can start with as few as 150 mealworms, but at least 500 is recommended.

• The more mealworms you start with, the faster your colony will produce a steady supply.

• Be cautious if purchasing superworms (Zophobas morio), as they are sometimes treated with insect growth hormones that make them sterile.

Step 2: Prepare the Breeder Box

• Use a large, shallow, smooth-sided container (about the size of a shoebox or larger).

• Plastic or glass is best—avoid wood or cardboard, as worms can chew through.

• A clear container lets you monitor frass (waste).

• Keep mealworms no more than 1 ½” deep to prevent overheating.

• Always use a tight-fitting, ventilated lid to prevent infestations. Drill holes if needed for airflow.

• If condensation forms inside the lid, add more ventilation.

Step 3: Add Bedding

• Fill the container with 2–3” of Mealworm Keeper (or another fine “meal” substrate such as bran meal, cornmeal, or oatmeal).

• Place your mealworms in the bedding.

Step 4: Provide Food & Moisture

• Add about ½ cup of raw vegetables such as potato, carrot, apple, or banana peel.

• Replace food every few days or when moldy.

• Use Thirsty Cricket (gel water source) or moist foods to keep worms hydrated.

• Too little moisture slows growth; too much can produce mold.

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Growing & Life Cycle

• Once prepared, leave the container undisturbed for several weeks.

• Mealworms will eat, then pupate, then become beetles.

• Adult beetles will lay eggs that hatch into new mealworms.

• For best results:

  • Temperature: ~80ºF

  • Humidity: ~70%

  • Keep the container out of direct sunlight.

  • If using a heat lamp, add extra moisture sources (Thirsty Cricket, raw veggies, moist sponge).

• Check regularly with a thermometer to prevent overheating.

Life Stages:

• Larvae (mealworms): ~4–6 weeks

• Pupae: 1–3 weeks

• Adult beetles: Reproduce and lay eggs until the end of their lifespan

• Eggs: Hatch in 1–4 weeks

⚠️ Important: Separate eggs and larvae from beetles—otherwise beetles may eat them. Remove dead mealworms and beetles promptly.

Maintaining Your Colony

• Mealworms take 3+ months to complete their cycle.

• As adults, beetles will reproduce, lay eggs, and die.

• Check bins daily:

  • Regulate temperature

  • Replace food

  • Remove dead worms/beetles

Using a Two-Container System

• After beetles appear, move them to a second Breeder Box with fresh bedding and vegetables.

• This prevents beetles from eating the eggs and larvae.

• The beetles will lay more eggs in the new container, continuing the cycle.

• Tip: Use apple slices to attract beetles, then shake them into the second bin.

Harvesting

• Once larvae are large enough, they can be fed to pets.

• To store for later: keep mealworms in the refrigerator (4–8 weeks).

• Any worms left in the container will continue their cycle into pupae and beetles.

• Always cycle beetles into a second container for continuous production.

Cleaning

• Once bedding is depleted or foul-smelling:

  • Remove larvae

  • Discard old bedding

  • Clean container thoroughly

  • Replace with fresh bedding and vegetables

• Sift out any eggs if needed before cleaning.

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Life Cycle Details

• Egg: Tiny, hatch in 1–4 weeks.

• Larva (mealworm): Molts several times over ~3 months. Newly molted larvae are white and soft before hardening to golden brown.

• Pupa: White to yellow-brown, non-feeding stage, lasts 1–3 weeks.

• Beetle: White/light beige at first, then hardens to red, brown, and finally dark brown/black. Lives several months and reproduces before dying.

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Supplements for Healthy Mealworms

To make your mealworms fatter and more nutritious, add supplements:

• ZooPro High Protein Supplement

• Calcium supplement (or finely ground eggshells)

• Wheat germ, soybean meal, fish flakes, bone meal, brewer’s yeast, graham flour, etc.

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Mite Prevention

Sometimes colonies get infested by grain mites (Acarus siro). They appear as tiny, whitish-tan dots and thrive in moist conditions.

• Always use Exotic Nutrition Mealworm Keeper to reduce risks.

• Prevent infestation by:

  • Floating bins in water (moat method)

  • Standing bins on legs in water cups

  • Coating bins with Vaseline barriers after cleaning

⚠️ If mites appear, discard the entire colony and start over.

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Notice: Exotic Nutrition cannot provide specific care guidelines on an individual basis. Please consult a veterinarian or experienced breeder.

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