Are Calci Worms the Same as Mealworms?

Scott TaylorJuly 21, 2022
Mealworms and calci worms are both common types of feeder insects for wild birds, reptiles, amphibians and local garden wildlife.

But when it comes to their differences, there's alot of confusion. Are they the same thing? Do they come from the same place? And most importantly, do they taste the same to birds and reptiles?

The answer to all of these questions is a resounding no. Calci worms are not the same as mealworms. They are two completely different creatures.

Let's take a closer look at the two to find out their differences.

Are Calci Worms the Same Type of Insect as Mealworms?

No, calci worms are not the same type of insect as a mealworm. In fact, there are some key differences in their entomology that you should be aware of. Take a look at the scientific definitions below:


Mealworms (Tenebrio molitor) are the larvae of the common darkling beetle. They're usually between 1 and 2 cm long, plump and have a smooth, shiny cuticle. They're a golden yellow colour, although they can sometimes look a little paler.

Calci Worms

Calci worms (Euroworms), on the other hand, are the larvae of the calci Grub. These grubs are actually a type of fly, not a beetle. Calci worms are usually between 1 and 2 cm long too but they're not as plump as mealworms. They also have a smooth, shiny cuticle but it's more of a translucent white colour.

Calci Worms vs Mealworms - Appearance

Ok, so now that the science is out of the way. You’re probably wondering, how do I tell the difference between a calci worm and mealworm?

Well, as you can see in the picture below, calci worms are a sort of yellow, grey colour while mealworms are brown or may also appear black in younger worms.

There’s also a big difference in their shape and size. Calci worms are a much thicker type of worm, while mealworms will tend to be a longer and thinner in length.

Calci Worms vs Mealworms - Nutrient Content

Another of the key differences to be aware of between calci worms and mealworms is their nutrient content.

Calci worms are higher in calcium, while mealworms are higher in protein. Calci worms are also slightly higher in fat when compared to the mealworm. Both calci worms and mealworms are good sources of other vitamins and minerals such a phosphorus.

What Birds and Animals Do Calci Worms and Mealworms Attract?

Birds that typically adore eating mealworms include Tits, Blackbirds, Robins, Starlings, Nuthatches, woodpeckers, wrens, and finches. You should try to avoid feeding mealworms to hedgehogs. The hedgehog happens to find mealworms quite addictive and can be harmful in large quantities.

Birds that typically enjoy eating calci worms include the Blue Tit, Sparrows and the Robin. Some of the birds mentioned above will avoid the calci worm due to its lower protein content.

Calci worms are also a good diet for certain reptiles such as bearded dragons, leopard geckos, and monitors. Some amphibians will also consume calci worms including: newts, frogs, toads, and salamanders. These invertebrates should only be given as treats to these animals as their main diet should consist of other items.

Calci Worms vs Mealworms - When I should feed these worms?

The best time of year to feed both calci worms and mealworms to birds is during the nesting and migration season when the parents are looking for high-protein foods to feed their babies. Saying that, birds will enjoy dining on these juicy worms at all times of the year.

Calci worms can be found in the early spring under decaying leaves and wood. If you have calci worms as pets, you can keep them in the refrigerator until you’re ready to use them as food for your bird friends.

Mealworms can be found all year-round as they are not affected by the cold weather. You can buy mealworms online or at your local pet store. If you choose to keep mealworms as pets, you can also keep them in the refrigerator until you’re ready to use them as bird food.