How To Keep Mealworms Alive: Things You Need To Know

  • By: Sam Richards
  • Date: May 30, 2022
  • Time to read: 7 min.

If you own exotic pets like reptiles, skunks, sugar gliders, lizards, and amphibians, and mealworms can be an excellent food source for them. Although these tiny creatures look like worms, they are actually the larval stage of darkling beetles. They can be maintained quite easily and provide essential fat and protein for your pets.

Although you can visit your local pet store to buy mealworms or get them online, some breeders prefer to raise their own mealworms. But this is not an easy task, since the slightest difference in temperature can make them transform into beetles, which makes them useless as feed. Furthermore, if they do not receive adequate water or food, they can perish quite easily. Here we shall discuss how you can keep them alive and raise them properly.

Things You Need

These are the different things you need in order to keep your mealworms alive and healthy:

  • Storage Container: For the purpose of storing mealworms, you can use a large container with shallow walls and smooth sides. The purpose of a large container is to provide extra space that allows for heat dissipation. If the container gets overheated, the mealworms will get suffocated and die. It is advisable that you use a glass or plastic container since mealworms can climb up cardboard or wood. They can also chew the wood and escape the container, so you are better off using a tough and transparent material that will allow you to keep an eye on the waste accumulation.
  • Bedding: At the base of the container, you should place bedding made of bran meal, oatmeal, or cornmeal. The material must be crushed to a powdered form so that the worms can be moved easily when needed. Keep the bedding at a height of 2-3 inches and replace it on a regular basis.
  • Feed: For feed, you may add half a cup of freshly cut vegetables. Cut raw carrots and potatoes into pieces 1-3 inches in length and add them to the container. Sometimes you may notice the food being pulled underneath the bedding by the mealworms, but this is no cause for concern.
  • Nutrients: Mealworms need a source of nutrition and you can use mealworm chow for this purpose. This has added vitamins, minerals, calcium, and protein that allow the worms to thrive. When you provide adequate nutrition to the mealworms, your pet will receive it as well.
  • Moisture: Mealworms may die from the lack of moisture so make sure to keep them hydrated. But be careful not to add regular water since the worms may drown and die otherwise. Raw vegetables are a good source of moisture, but you can also use gel water sources available in the market and add them to the bedding. Some of these water sources contain calcium, which is essential for mealworms.

Starting The Colony

Unlike other animals, mealworms do not require intense monitoring, but there are some basic things you need to keep in mind. You should use a ventilated screen cover rather than a plastic lid to prevent the container from getting overheated.

The temperature of the container should be approximately 75 degrees Fahrenheit. This allows them to thrive, breed, and lay eggs. If you are struggling to maintain the temperature, you can place an incandescent bulb at the top. Make sure the temperature is not too high otherwise the worms will die. In order to keep track of the temperature, you can attach a thermometer to the container.

When the humidity of the container is high, the mealworms will breed at a faster rate. If you live in a place where the climate is quite dry, you need to take additional measures to increase the humidity inside the enclosure.

For this purpose, you can place a tall glass of water inside the container that can enhance the humidity. You need to ensure the worms cannot easily climb the glass and access the water because that will kill them. You can measure the humidity of the container using a hygrometer.

What Kind of Mealworms Should You Purchase For a Starter Colony?

While starting a mealworm colony, you should get yourself larger mealworms, since they will transform into beetles much faster compared to the smaller ones. After maturing into darkling beetles, they start breeding quickly. These eggs will hatch into mealworms, but you should get the beetles out of the container as a precaution because some of the beetles might consume the eggs.

While in the market, you might come across “giant mealworms” but you should avoid them at all cost. These worms are injected with growth hormones and they don’t transform into beetles, thus foiling your plans of starting a colony. You shouldn’t breed super worms either, since they cannot be bred easily.

It is advisable to buy a lot of mealworms at once while starting a colony. This gives you a couple of benefits:

  • A large number of worms make the colony much more sustainable.
  • By buying in bulk, you can save some money.

Keeping the Container Clean

In order to keep the mealworms alive, you should make sure the container remains clean. You should scan the enclosure for worm corpses on a regular basis. Their bodies turn dark brown after dying, so you can easily identify and get rid of them. Your pet reptiles won’t eat dead worms, but you can feed them to plants as organic matter.

Normally, the smell of the container depends on the bedding, but if don’t clean it regularly the dead bodies of worms together with the excrement can generate a foul and strong odor. On a monthly basis, you should get rid of the excrement, replace the bedding, and clean the container. This way, you can prevent the growth of bacteria, mold, and fungus.

Feeding the Mealworms

In order to fatten up the worms for your pets, you should supply them with essential nutrients. You shouldn’t only depend on the bedding and use fruits and vegetables that will turn them healthier. If you have leftover food scraps and celery bottoms, you can use them as feed as well.

Mealworms are voracious eaters so you will have to replenish their food source on a consistent basis. You should remove any rotting food scraps since they can attract pests and mold. In order to ensure a steady supply of minerals and vitamins, you can rotate the food items.

Long-Term Storage Options

If you wish to prevent the mealworms from metamorphosing into darkling beetles, you can keep this at a low temperature so you can feed them to your pets. When you store them inside a refrigerator, they turn dormant at the metamorphosis process is delayed, thus preventing them from transforming into beetles.

Mealworms normally prefer to live in an environment having a temperature of approximately 70 degrees, but you’d want this to be lower if you wish to delay the metamorphosis. At higher temperatures, the worms consume food rapidly and turn into beetles rapidly. Refrigerating the worms is similar to cryogenic freezing and it deactivates their hormones, extending their larval stage by two months or so.

Generally, you can use the worms as feed for up to 3 weeks, after which they turn into pupae. If the climate is not suitable for metamorphosis, they might perish. By refrigerating, you can use the worms for 6-10 weeks. It is advisable that you take out the worms from the freezer once every week and allow them to feed for an entire day at normal temperature. After this, you can get rid of the remaining food scraps and freeze them again.

You need to maintain a balance while fattening the worms for the long-term. They can survive in the larval stage for about a year before transforming into pupae. If you feed them too much, they can transform quite swiftly and you don’t want that to happen. On the other hand, too little nutrition can lead to their death and prevent them from growing.

Feeding The Mealworms To Your Pets

Reptiles normally love to eat mealworms, but some of the larger species may not fancy them because of their small size. If you find that your pet is not eating the worms, you can rotate the food by offering them insects like flies, locusts, and crickets. After that, you can attempt to feed them the mealworms again.

Even if your pet likes eating mealworms, you should rotate their food so that they don’t get bored of it. If your pet refuses to eat the worms, it might be because of the fact that they are motionless or dead. So you should make sure they are moving by putting some vegetables and fruits in the feeding bowl.


By being committed and using the right resources, you can raise a mealworm colony effortlessly. The upkeep is quite low and you don’t even need to clean the container too often. By following the tips mentioned above, you can raise your own healthy mealworms, keeping your hungry pets satisfied and saving some money in the process.

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