Should Leopard Geckos Eat Mealworms? Pros, Cons, Myths

Lots of arguments have been had for and against feeding leopard geckos only mealworms, so we decided to have a look for ourselves to see whether or not a diet of only mealworms is a good idea for your leo. 

Leopard geckos, being insectivores, should be fed exclusively on insects. However, this doesn’t mean that you should pick one insect – like mealworms – and only feed them that. 

A variety of feeder insects will not only provide your leopard gecko with an array of nutrients, but the different types of insects (worms, roaches, crickets) will also stimulate their hunting instincts differently. 

But how do you decide which insects to give to your leopard gecko or know how nutrient-rich mealworms really are? 

In this article we’ll cover all of that as well as:

  • how to gut feed the mealworms, before feeding them to your leopard gecko
  • how to deal with an overweight leopard gecko (and keep them from becoming overweight), and
  • bust a few myths about mealworms as food for your leopard gecko. 

The Pros and Cons of Mealworms As Feeder Insects For Your Leopard Gecko

can leopard geckos eat mealworms

Below we’ve listed the pros and cons of using mealworms as feeder insects for your leo. It should be noted that mealworms can be fed from the time that your leopard gecko is a baby to adulthood. Keep reading to find out how much and when you should feed your leopard gecko. 

Pros:

  • Mealworms are readily available from pet shops and can also be bought online
  • Mealworms are quite cheap and you don’t have to “buy in bulk” in order to try and save some money
  • You can also start your own breeding colony quite easily (mealworms are the larvae of darkling beetles)
  • No smell (unlike crickets)
  • No or very little mess 
  • Mealworms can be kept in a refrigerator until needed, then thawed, and gut-loaded before feeding them to your leopard gecko
  • Even when not kept in a refrigerator, mealworms have quite a long lifespan before they turn into pupae.
  • Mealworms don’t bite (unlike, say, crickets)
  • Because they are relatively slow-moving, they won’t escape the feeding dish like some of the other feeder insects. 
  • You can buy freeze-dried mealworms for the odd occasion, for example when you go away on holiday and someone else needs to feed your leo while you’re gone from home for a few days. It can be much easier to feed the freeze-dried worms a few times instead of having to teach someone how to gut-feed the live worms. 

Cons:

  • Mealworms contain a lot of chitin, which can be difficult to digest and may lead to impaction in some cases. 
  • Mealworms do not contain enough calcium to supply adequate levels of calcium to your leopard gecko’s diet. 
  • The calcium and phosphorus ratio of mealworms are not ideal. 
  • The fat content of the mealworms are quite high (12.7%). 
  • Mealworms are not a very stimulating prey for your leo – unlike crickets or roaches which they have to do quite a bit of work to catch sometimes. 
how to gut load mealworms for leopard geckos

Mealworms And Other Leopard Gecko Feeder Insects And Their Nutritional Profile

Because Leopard geckos are relatively small, their prey also needs to be quite small in order for them to catch and eat them without getting injured or impacted. 

Leopard Gecko Feeder Insects Include:

  • Mealworms (Tenebrio molitor)
  • Crickets (House crickets) (Acheta domestica)
  • Dubia Roaches (Blaptica dubia)
  • Silkworms (Bombyx mori)
  • Waxworms (Galleria mellonella)
  • Butterworms (Chilecomadia moorei)
  • Phoenix Worms (Black Soldier Fly Larvae) (Hermetica illucens)
  • Hornworms (Manduca sexta)
  • Superworms (Zophobas morio)

Mealworms, crickets, and Dubia roaches (small or medium) are the most popular feeder insects for leopard geckos. 

The Nutritional Composition Of Feeder Insects For Leopard Geckos 

Insect NameProtein %Fat%Moisture% Fiber%Calcium/Phosphorus Ratio %
Mealworms20.2712.7262.441.730.04
Crickets21.326.0169.073.20.081
Dubia Roaches (Medium)19.66.770.82.90.308
Silkworms9.31.182.71.10.075
Waxworms15.5022.1961.737.690.131
Butterworms15.5029.460.21.4
Phoenix Worms15.587.8168.183.461.52
Hornworms102.4852.5
Superworms17.4117.8959.376.800.053
Sources of Nutritional Information:
GrubCo Nutritional Information
Dubia Roach Nutrition Facts 
Nutritional Value of Commercially Raised Insects
Timberline: Hornworms

How Mealworms Weighs Up Against Other Leopard Gecko Feeder Insects

Crickets (House crickets) (Acheta domestica)

Pros: low in fat and high in protein, stimulating to hunt

Cons: the smell, they can get away from you easily… and hide very easily

Dubia Roaches (Blaptica dubia)

Pros: gut-loads very well, long lifespan, good nutritional makeup 

Cons: can be expensive, can’t ship everywhere 

Silkworms (Bombyx mori)

Pros: low fat, no smell

Cons: expensive and not always easy to find 

Waxworms (Galleria mellonella)

Pros: leo’s really love them

Cons: very high fat content; should be used more as a treat, smells 

how many mealworms to feed a leopard gecko

Butterworms (Chilecomadia moorei)

Pros: leopard geckos love them

Cons: extremely high fat content – definitely an occasional treat, 

Phoenix Worms (Black Soldier Fly Larvae) (Hermetica illucens)

Pros: low fat, cheap and easy to find

Cons: messy and leo’s often dislike them 

Hornworms (Manduca sexta)

Pros: low fat, not smelly or messy

Cons: expensive

Superworms (Zophobas morio)

Pros: easy to care for and no refrigeration necessary, no smell

Cons: can bite, lower in protein, too big for juveniles and even many adult leopard geckos 

How To Prepare Mealworms For Leopard Geckos

When you buy mealworms as food for your leopard gecko, you need to prepare them first (unless they’ve been freeze-dried, obviously).

This is called “gut-loading” and is used to make the mealworms as nutritious as possible for your leo. However, all live food should be gut-loaded before being fed to your leo. 

How Gut-Loading Works 

Gut-loading takes place in the 24 hours before they’re going to be fed to your leopard gecko. During this time, you need to:

  • Remove the mealworms that you’re going to use as food from the fridge and let them return to room temperature. Be careful that you don’t try to “help them along” by adding heat of some kind (say, placing them in strong sunlight … or worse) and then killing them. 

Once they’ve reached room temperature, you should see that the mealworms are wriggling about more than when you just removed them from the fridge – when they may have even appeared dead. 

Tip! If you live in a very warm part of the country or you’re going through a heatwave, you may actually have to put your mealworms in a cooler part of the house to let them slowly warm up to room temperature. 

  • Feed the chosen mealworms on nutritious food like fruit and vegetables or bug grub. Keep reading for a list of the best foods you can use for gut-loading.
  • Once the mealworms have eaten their fill, you just need to dust them with calcium and/or vitamin powder and then you can feed them to your leopard gecko.  

Tip! When you take the container of mealworms from the fridge, you can do an inspection of the worms and ensure that they are still healthy. You can also remove any dead worms from the container at this time. They make great bird feed, so you can just toss them into the garden.  

can mealworms bite leopard geckos?

Foods To Use For Gut-Loading Mealworms

There’s a wide variety of food that you can use for gut-loading your mealworms as they’ll eat almost anything you put in front of them. However, you need to remember that you’re going for nutritious foods and not necessarily the cheapest foods. 

So, where you can, rather feed fresh foods or bug grub. Rather steer clear of pet food (fish, dog, and cat food) and treats as these can contain colorants, additives, etc. that you don’t want to feed to your leopard gecko. 

Here’s a list of fresh foods you can feed your mealworms to gut-load them:

  • Carrots (cut into slices or chunks)
  • Apples (cut into slices or chunks)
  • Potatoes (cut into slices or chunks)
  • Sweet potatoes (cut into slices or chunks)
  • Squash (cut into slices or chunks)
  • Dark, leafy green (you can tear these with your hands to make them easier for your mealworms to eat)

Here’s a list of fresh foods you shouldn’t feed your mealworms:

  • Citrus fruits (oranges, lemons, etc.)
  • Onions 
  • Avocado
  • Foods your leopard gecko can’t eat

Dusting The Mealworms With Calcium And/Or Vitamins 

Just like you need to gut-load the mealworms to give your leopard gecko extra nutrients, you also need to dust the mealworms with calcium or vitamin powder before feeding them to your leo. 

These extra calcium and vitamins – especially vitamins A and D – are important as they give your leo the extra vitamins and minerals that they may need in their diet. Insectivores, like leopard geckos, are often deficient in calcium, vitamin A, and vitamin D according to a 2014 study

How To Dust Mealworms With Calcium Or Vitamin Powder 

To dust mealworms with calcium or vitamin powder, simply take the gut-loaded mealworms and place them either in a small, sealable container or a small plastic bag. 

Add a small amount of the calcium or vitamin powder and carefully shake the bag or container a little in order to cover the mealworms in the powder. This “dusting” of powder is all you need to add to your leo’s diet at a time. 

You can then go ahead and feed the mealworms to your leopard gecko and you’ll notice that they don’t mind the extra dusting of flavor on their food! 

why are mealworms bad for leopard geckos

How Often You Should Supplement Your Leopard Gecko’s Food

How often you supplement your leopard gecko’s food by dusting the gut-loaded mealworms depends on the health of your leo. For example, if you know that your leo has a specific deficiency of vitamin D or calcium after a vet visit, you’ll probably need to supplement more often. 

A good rule of thumb to follow for supplementation for your adult leopard gecko is:

  • One meal per week dusted with a calcium supplement, and 
  • One meal per week dusted with a vitamin supplement. 

For a juvenile leopard gecko, you can dust the same as for an adult, but for a baby leo, you need to dust as follows:

  •  Three meals per week dusted with a calcium supplement, and 
  • One meal per week dusted with a vitamin supplement. 

Make sure that these are supplemented on alternative days. 

Note! If you’re at all worried that your leopard gecko needs extra supplementation, speak to your vet. They will also be able to tell you if they perhaps need less supplementation depending on their specific diet and needs.  

How Often And How Many Mealworms Should You Feed Your Leopard Gecko?

Although each leopard gecko has a slightly different appetite and the table below shouldn’t be considered set in stone, it does give a good idea for what you should start with. 

Age in monthsHow often feedHow much feed
0 – 6BabyDaily5 – 7 small mealworms
6 – 12 JuvenileEvery other day5 – 7 small mealworms 
> 12AdultEvery 3 – 4 days 6 – 7 large mealworms 

Can Mealworms Make Your Leopard Gecko Overweight?

Although mealworms have a lot less fat in them than, say, waxworms, butterworms, or even superworms, you still need to watch out when you feed your leopard gecko mealworms that you don’t feed them too much. 

Although most leos will stop eating when they’re full, there are those who will keep eating as long as there’s food available. So, if you’re feeding until your leopard gecko stops eating and you have one of the latter, you’ll have a plump critter on your hands before long. 

It’s therefore not so much the fact that they’re eating mealworms that’s the problem, but the fact that they’re eating too much. 

Keep reading to find out if your leo is overweight and steps you can take to slim them down in a healthy way. 

Can Overweight Leopard Geckos Be Fed Mealworms?

A lot has been said about a leopard gecko’s diet and what they can and can’t eat when they’re overweight. You can still feed an overweight leo mealworms, but you have to be careful with the amount of mealworms and food overall that you’re feeding them. If you can avoid mealworms for the time being, rather do. 

For example, if you looked at the feeding chart and thought ‘that is really not enough food’, you’re probably overfeeding your leopard gecko. Don’t beat yourself up though, we all go through a steep learning curve when it comes to new pets! 

Can you feed leopard geckos just mealworms

How To Tell If Your Leopard Gecko Is Overweight 

You can tell whether your leopard gecko is overweight by looking at specific characteristics of your leo. And overweight leopard gecko will have:

  • A tail that is as wide or even wider than their head, usually also with a thick base  
  • A sunken backbone
  • Their legs will look fat and be soft when you touch them (you’ll feel fat, not muscle)
  • Their head will look almost distended 
  • Looking from above, their belly will be very round and full and may drag along the ground
  • They’ll move slower and won’t move around as much, for example not climbing around  
  • Some fat leopard geckos have air bubbles in their armpits 

Illnesses To Watch Out For If Your Leopard Gecko Is Overweight 

Besides the wear and tear to your leopard gecko’s joints and organs because of the extra weight that they’re carrying around, your leo can also get fatty liver disease (FLD) and xanthomatosis (fatty deposits under the skin) if they start to lose weight too rapidly. 

If you need to put your leopard gecko on a diet, speak to your vet first and let them guide you in the best way to do this. 

Can Mealworms Cause Impaction In Leopard Geckos?

One of the things that leopard gecko parents are probably most worried about, is whether or not mealworms will cause impaction in their leo because of the high levels of chitin in mealworms. 

The good news is that in most healthy leos, mealworms don’t cause impaction. The bad news is that, on the odd occasion, mealworms may cause impaction, especially if your leo isn’t healthy. 

If you want to know more about impaction in leopard geckos caused by mealworms, you should read our article on that here!

The Symptoms Of Impaction In Leopard Geckos

If you’re worried that your leopard gecko is impacted, have a look at this list of symptoms to see how accurately it matches your leo and whether you need to consult the vet.

  • Swelling of their abdomen 
  • Reduced activity/lethargy (reduced activity during brumation doesn’t count, but if they have a swollen abdomen, etc. it’s best to have it checked by the vet and not to just leave it. It can mean the difference between their life and death)
  • Loss of appetite 
  • Constipation
  • Vent prolapse 
  • Cloaca licking 

Other Mealworm FAQs

Finally, let’s answer some of the mealworm questions that are also drifting around the internet – can mealworms bite your leo and can they bite your leo after being eaten alive and basically eat their way out of your leopard gecko?

Can Mealworms Bite Your Leopard Gecko?

Mealworms can indeed nip with their jaws, but these bites are for the most part not problematic and leopard geckos soon learn how to eat mealworms in a way that will crush them before they can bite.

If you’re worried about bites, you can crush the worms’ heads before feeding them to your leopard gecko. 

Also make sure that you feed the correct size mealworm for your leo’s size and age (as stated in the feeding table above). Worms that are too large can not just lead to choking, but can also give your baby leo a sore bite.  

Can Mealworms Survive After Being Eaten And Bite Through Your Leopard Gecko’s Stomach?

Are mealworms good for leopard geckos

Although a mealworm may be able to survive being eaten, the acidic environment of your leopard gecko’s stomach will ensure that the mealworm won’t be alive much longer, and not long enough to chew their way out of your leo all Alien-style. 

If it’ll make you feel better, you can crush the worms’ heads before feeding them to your leopard gecko. However, there is absolutely no need for that.

Conclusion 

When it comes to your leopard gecko’s diet, mealworms are a good choice, but shouldn’t be the only thing that you’re feeding them. Rather than only feeding your leo mealworms that have been gut-loaded and dusted, feed your leo a selection of feeder insects like crickets, roaches and different types of worms. Your leo will be the healthier for it! 

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