How to Breed Mealworms

Mealworms are commonly used as food for birds, chickens, fish, reptiles, rodents, and other pets. If you have several animals that consume mealworms, breeding them at home can be a highly practical and economical choice. Raising mealworms is not as expensive as you might think, and it requires minimal effort to maintain them.

Gather the materials:

• Dry oats or cornmeal
• An organic moisture source that doesn’t mold easily. Carrots are an excellent option, but you can also use other vegetables and fruits like potatoes or chopped apples.
• Three plastic containers with holes in the lids.
• Some cardboard pieces like egg cartons or toilet paper rolls.
• Mealworms, also known as beetle larvae. You can start with around 500-1000 worms.

Place a thick layer of oats or cornmeal about 2.5 cm deep at the bottom of each plastic container. This will serve as both bedding and food for the mealworms during various stages of their development.

Add a few slices of vegetables to each container. You can use any type of fruit or vegetable, such as celery, lettuce, potatoes, or apples. Carrots tend to mold more slowly compared to other fruits and vegetables. If you opt for a different humidity source, remember to change it regularly.

Pour the mealworms into one of the containers. Some mealworm breeders like to add slices of bread, ground cereal, or dry dog food into the mix.

Place a few pieces of cardboard on top of the oats layer. These tiny creatures prefer the dark.

Label the containers. You will use one container for breeding the mealworms (larvae), another for the pupae, and a third for the adult beetles.

Close the lid of the box and place it in a dark, warm spot. The warmth will speed up the mealworm lifecycle, causing them to pupate faster when kept warm.

Regularly maintain the mealworm containers. Some people prefer checking them daily, while others do it once a week.

• Remove any decaying fruits, dead insects, or mold patches from the oatmeal bedding at the bottom of the container.
• Add more vegetables and oatmeal if needed, and stir the bedding to prevent mold growth.

Keep an eye on the pupating mealworms in the container. Depending on the temperature and the age of the mealworms when purchased, the pupation process may take anywhere from a week to several months.

• Development is marked by a gradual darkening of the color at all stages of the insect's lifecycle.
• The newly formed pupae are pale white and look more like tiny curled-up beetles than mealworms.
• You may notice the mealworms shedding skin multiple times before they pupate. This is normal.

Separate the pupae as soon as you spot them. You can use tweezers if you find it too unpleasant.

• The pupae are inactive and do not require food. Humidity does not harm them, but they do not consume the moisture source in the box either.
• It's crucial to separate the pupae from larvae and adult beetles, as the pupae have no defenses and are vulnerable to being eaten before they can emerge.
• The pupation stage lasts from one to several weeks, depending on the ambient temperature. You will know the pupae are ready to hatch when they start to darken.

Regularly inspect both containers to observe the different developmental stages of the mealworms. This becomes even more important when you have a variety of insects in different stages of growth.

Immediately remove the adult beetles from the pupation box. If you delay, they will begin eating the pupae.

• Transfer the adult beetles into a separate box with conditions similar to the mealworm box. Adding a little extra oatmeal is helpful as it provides more shelter for the beetles.

Regularly check the adult beetle container for eggs. The more adult beetles you have, the more eggs will be laid. Typically, you'll find the eggs at the bottom of the container.

• You don't need to remove the eggs, but they indicate that more larvae (mealworms) are on the way.
• A female adult beetle lays about 500 eggs at a time.
• The eggs will hatch within 4-19 days, depending on the surrounding temperature.

After the mealworms hatch, transfer them from the adult beetle container to the mealworm container. Since the female beetle lays numerous eggs, you will have a significant amount of larvae to care for with each batch.

Continue with daily or weekly care for the mealworm container. This includes replenishing food and moisture sources, separating the insects by their developmental stages, removing the deceased, and stirring the bedding regularly.

• If you notice that the mealworms are multiplying faster than your pet can consume them, you can either prepare the insects for eating or humanely freeze some to reduce their numbers. Do not release them into the wild (mealworms are not native to North America). Alternatively, you can feed the pupae to adult beetles or place any leftover mealworms in a bird feeder in your backyard.

• Avoid overcrowding the mealworms in a single container.
• Keep in mind that mealworms are nocturnal and will not move much during the day. If you notice them sluggish in the morning, don't immediately discard them thinking they are dead.
• If you're raising a small number of mealworms, you can use a smaller container, such as a Kritter Keeper.
• Frequent cleaning of the container is not necessary.
• Keep the containers cool. Mealworms prefer cooler temperatures.
• Don't forget to replace the old moldy food in the container.
• To allow the mealworms to pupate, you should house them in separate containers.
• Mealworms thrive best in an environment with temperatures around 24 - 27°C, though any temperature within this range is suitable.
• You can follow these guidelines for raising rice worms, but avoid placing them in the fridge. Rice worms are tropical creatures and prefer room temperature.
• Mealworms stored in the fridge will grow slower. If you plan to feed your pet mealworms instead of adult beetles, you should store them in the fridge.
• Be sure to feed them some protein sources, such as other types of insects.