What Exactly Are Mealworms?

If you have pet birds or livestock, or if you’ve even set foot in a pet shop, you’ve probably seen mealworms advertised before. Or, perhaps, you’ve heard someone complaining about mealworms getting into their stored cereals and other goods. You probably have some idea of what mealworms are, but what are they exactly?

lots of mealworms

Mealworms are the larval form of the yellow mealworm beetle, Tenebrio molitor, a type of darkling beetle.Mealworms aren’t really worms but they look like them, complete with a segmented body and a pale tan color. A known food pest, they’re commonly used as food for birds and reptiles, and also as fishing bait.

Mealworms are creepy and crawly, but unless they’re breaking into your stored flour or other foods they really aren’t much to worry about.

But if you own chickens, ducks, or any other kind of bird, or have reptiles as pets, you probably want to learn more about them since they are an important food source for these animals. Keep reading and I’ll tell you everything you need to know about these mealworms!

What Do Mealworms Look Like?

Mealworms look a lot like what their name suggests: they are tan or brown, segmented worms, with a small but noticeable head and easily distinguished body segments.

The heads and the tips of their tails are darker than the rest of their body and if you look very closely, you can see tiny feet and antennae.

They rarely grow larger than an inch in length, but some can be considerably bigger, specifically those from different species of darkling beetle.

How To Breed Mealworms! Mealworm Farming 101

What Do They Turn Into?

Mealworms, as mentioned, turn into adult beetles, specifically darkling beetles. So named because they have a dark glossy black carapace and purple-brown legs.

Contrary to what some sources might have you believe, mealworms don’t stay mealworms forever if they’re kept alive; eventually they will mature, enter their pupa stage, and then emerge as adults.


Understanding the mealworm life cycle is important for dealing with them as pests, or also rearing them yourself as food for your other animals.

As with all insects, life begins in the form of an egg, laid by a female adult after having been fertilized by a male adult.

Females are incredibly prolific when it comes to reproduction, and they might lay upwards of 400 to 500 eggs in their lifetime, over the course of a year or a little longer. Obviously, if you have an infestation in or around your home, that growth curve is truly exponential!

Anyway, the tiny white eggs will eventually hatch into small mealworms within 7 to 30 days. The mealworms, as mentioned, are the larval stage and will last for a couple of months as a rule. Mealworms eat the entire time, molting as they grow, getting bigger and bigger.

Eventually, once they reach their maximum size and environmental conditions are right, they enter their pupal phase, becoming immobile, ceasing eating, and developing in a sort of hibernation for weeks to a couple of months, highly dependent on the temperature and humidity.

Once this phase of development is complete, an adult beetle emerges, heading out to mate and continue the mealworm lifecycle.

I’ll put it to you this way: if you detect even a handful of mealworms infesting your goods or elsewhere on your property and you don’t put a decisive stop to it, in a year’s time you could have literally thousands and thousands of the things crawling around- and they will all be “getting busy” if you know what I mean!

Role in Nature

Aside from being pests and snacks for poultry, what do mealworms do in nature?

As you might have already guessed, they and many other insects like them are important contributors to the process of decomposition, breaking down all kinds of edible organic matter into the soil, and contributing to soil fertility, condition, and nutrient levels by their growth, waste, and even their death.

And, also as expected, mealworms are a critically important food source at all stages of life for many other wild animal species.

Are Mealworms Harmful or Dangerous?

No, not explicitly. Mealworms, whether they are actually mealworms or adults, cannot bite, sting, or hurt you. They are not toxic and not truly dangerous in any way.

However, they can contaminate stored food, particularly fruits and vegetables, grains, and anything else they can eat and as mentioned they eat a whole lot!

This will greatly speed decomposition and contamination, and food that has been under the attention of mealworms will either be eaten or break down into a nasty slop that isn’t safe to consume.

Generally, the prescription is to throw out such contaminated food, especially considering it might already contain the next generation of beetles late in it if they’ve reached the adult phase.

What Kinds of Animals Eat Mealworms?

All kinds of animals will eat mealworms, as they’re a great source of protein, fat, calories and certain vitamins and minerals.

Their major predators are birds of all kinds, especially chickens but also many songbirds like blue jays, finches, and robins. Ducks and turkeys will also munch on mealworms.

Amphibians and reptiles are also regular eaters, with all kinds of lizards, frogs and turtles eating them up in abundance, and owners of these animals are already well acquainted with budgeting for mealworms, especially for native species that are primary predators of these insects.

Other than that, fish, other insects and arthropods, including scorpions, spiders, centipedes and even certain wasps will eat them, and believe it or not mammals will eat them also.

Hedgehogs, rats, and other small rodents and related critters will be more than happy to dine on them in the wild or in captivity.

You Can “Farm” Your Own Mealworms to Save Money

It sounds gross and weird, but if you have chickens, ducks, or just one or two pets that eat mealworms you can save yourself a bundle by easily farming your own.

You can get fertilized eggs online, live mealworms or adult beetles to start your own mealworm “farm” in a small plastic tray kept in the appropriate conditions.

It’s a lot easier than you think, and giving your mealworms some old produce (apples, pears, pumpkins, bananas, carrots, lettuce and other leafy veggies are great), a little bit of substrate, and keeping them in comfortable conditions means they will grow, develop, and reproduce with explosive speed.

You don’t need to give your ‘worms stuff at the peak of freshness; they are happy to munch on stuff that is wilting or even decaying.

This means you’ll always have a supply to give your animals and you’ll certainly be saving a bundle on supplements and treats!

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