Can You Feed Crested Geckos Mealworms?
By: Jason
Last Updated: February 23, 2023
Eating many different foods, including a range of live feeder insects, is vital for a crested gecko to stay healthy. Sadly, not all bugs are good for them. What about the larva of the darkling beetle? Can crested geckos eat mealworms?
Take great care in feeding crested geckos mealworms. While they have a lot of protein, some owners report they are difficult for cresties to digest and can cause impaction. Keepers who use mealworms point to the other factors driving the bowel issues.
Crested gecko owners and breeders have strong opinions about mealworms. Keep reading to get all the info to make an informed decision!
The Debate
The internet has a lot to say about feeding mealworms to crested geckos.
While a lot is in dispute, not everything is.
Agreed upon information
There are some aspects where people seem to agree. They include:
- Mealworms have a hard exoskeleton made up of chitin.
- Many of the insects that crested geckos eat without problem, including crickets and dubia roaches, have chitin.
- Some crested geckos get impacted while on a diet of mealworms.
- Some keepers feed crested geckos mealworms and do not have cases of impaction.
- Impaction is a “secondary condition” that results from poor diet, temperature issues, and other habitat problems.
- Captive reptiles need many different nutrients to be healthy. No “whole foods,” like apples or crickets, contain all the vitamins and minerals a body needs, so eating a variety is good.
- The nutritional value of feeder insects varies based on their diet and living conditions.
Expert opinions
A few experts made helpful comments.
Dr. Mark Finke, the author of more than 25 peer-reviewed articles on animal nutrition (including reptiles), says, “statements like ‘some insects are too hard’ or they ‘contain too much chitin’ … and thus are inappropriate for some species of insectivores are commonly encountered online [and] those statements have little basis in fact.”
Unfortunately, there is little research on which lizards have the enzyme chitinase and nothing on crested geckos.
Anthony Caponetto, a breeder since 2004 and one of the largest producers of crested geckos, writes that it is a myth that cresties can’t eat mealworms. He says we need to be careful with how many worms we offer so cresties don’t overeat.
Plenty of research-driven experts say that crested geckos should stay away from mealworms. Mariah Healey, a reptile husbandry specialist and consultant, advises avoiding mealworms because they are “potentially difficult to digest for cresties, leading to impaction in some cases.”
What do we do with this?
What do we do with all that info? We consider it, along with what follows on this page.
If you get finished reading this and decide to avoid mealworms, there are plenty of other live feeder insects to offer to your crested gecko instead.
If you opt to use mealworms, limit how often you offer them, only give a few at a time, and provide your crested gecko top-tier husbandry to minimize the chance of impaction.
Species Overview
Mealworms (Tenebrio molitor) are the caterpillar (or larval form) of a species of darkling beetle. While they may look the same, they are different from superworms.
Life cycle
Like other beetles, their lifecycle follows four phases; egg, larva, pupa, and adult.
Adult female darkling beetles lay several hundred eggs at a time. These tiny white eggs hatch one to two weeks later.
In its larval stage, the mealworm eats and grows. It sheds (or molts) the hard outer layer five to seven times as it needs more space. Mealworms will stay in this state for 8-10 weeks before they change into a pupa.
The pupating process takes about three weeks. This pupa goes from white to brown before the bug appears as an adult beetle.
The complete life cycle from egg to end of life as an adult is around one year.
Diet
Wild mealworms eat decaying plant matter, seeds, animal waste, and fungi. They love grains and are agricultural pests.
Captive mealworms eat nearly any organic matter fed to them; scraps of fruits and vegetables, grains, birdseed, and even cat and dog food.
Mealworms raised as live feeder insects need to be fed foods that are good for the animals that will eat them. A diet of grains (like rolled oats or barley), veggies (like carrots, kale, or romaine lettuce), and scraps of fruit (like apple or papaya) will help them grow and load them up with nutrients.
Nutritional Value
We always want to look at the nutritional value of any food we might feed to our pets.
How a person feeds and cares for an insect will change its nutritional composition. If you look around, you will find a range of results online.
Mealworm
- Protein – 18.7%
- Fat – 13.4%
- Fiber – 2%
- Moisture – 61.9%
- Minerals – 0.9%
- Calcium (Ca) – 169 mg/kg
- Phosphorous (P) – 2950 mg/kg
Mealworms have a decent nutrient makeup, which is why they are well-liked feeder insects for reptiles, birds, and amphibians.
Problems can occur if we feed too many of these to our pets. Their high-fat content makes them tasty and will put on some weight, and pets tend to gorge themselves and eat as many as possible.
Like most other feeder insects, they have far too little Ca for their P content and need a calcium supplement.
Mealworms are an average food source for reptiles, and they get a lot of use because of how easy they are to raise and keep.
Feeding Instructions
Size
Crested geckos can eat smaller insects. The space between their eyes is a good unit of measure for the length of the piece of food.
Mealworms range in size from 1/4″ (6 mm) to 1 1/2″ (38 mm) in length, though one inch long (25 mm) seems to be typical. Many sellers offer a few sizes.
Compared to many other insects, mealworms “hold their size” longer. Why is this useful? Fewer worms will get too big for your pet, and you don’t need to shop for live feeders as often.
Gut loading
Like almost all live feeders, mealworms need to eat healthy foods before you feed them to your crested gecko. This process is called ‘gut-loading.’
Much of the nutritional value comes from what is in the insect’s gut when your pet eats it. We want to maximize this by feeding the mealworms a nutrient-packed diet about 24 hours before feeding them to our pets. Too soon or too long, and your pet gets fewer nutrients.
To ‘gut-load’ your mealworms, either feed them a premade gut-loading diet or give them a grain, a dark green leafy vegetable, and a piece of fruit.
Dusting
Immediately before serving the mealworms to your crested gecko, you’ll need to dust them or coat them in calcium powder.
When possible, use ultrafine powder.
To coat, first, place the worms in a small container. Then, sprinkle some powder on them. Gently swirl the cup to get the dust to coat them evenly. Now they are ready to go!
Don’t apply powder to any worms you are not offering up right away. The powder will fall off over time.
Where do I feed the mealworms to my crestie?
Unlike other live feeder insects, mealworms don’t engage the ‘hunting instinct’ for crested geckos. They wriggle about but don’t run or hop, so there isn’t much “hunting” when they feed.
There are two ways to give the mealworms to your crestie.
Many keepers put insects directly into the enclosure with their crested gecko in an escape-proof bowl. (Mealworms will crawl out of short-walled cups and burrow in the substrate or under the paper.) This approach lets your pet eat as they like.
The other option is to hand-feed them with tweezers or tongs.
How often can I serve them?
Insects are a once-a-week food for adult crested geckos, but mealworms are better less often.
Ideally, your pet should mostly eat powdered gecko food with some live feeder insects and a bit of fruit every once in a while. This mix will give them all the vitamins and minerals they need.
Some keepers have reported that their cresties have had difficulties digesting mealworms and thus avoid them. Others who serve them cite only giving their pet a few per meal. Lizards that hunt quick-moving insects may go into a feeding frenzy and gorge themselves on a bowl full of tasty bugs that can’t escape.
Serve a range of foods for the best health. If you opt to use mealworms, do so as a treat!
How many should I give?
The general guide is to feed as many insects as a crested gecko can eat in fifteen minutes, but mealworms are a treat.
Start by giving your pet only one or two (depending on their size) at a time. Couple them with other live feeder insects to make it a meal.
The size of the lizard and the size of the worms change this answer as well.
Dead or alive?
Freeze-dried mealworms are readily available, but most crested geckos prefer eating live insects over dead, freeze-dried, or canned ones.
To freeze-dry something, you remove all the water. It gets firm and crunchy but lasts for a much longer time. Since water is one of the things we want for our pet lizards, this is a notable downside. Also, dust doesn’t stick to them very well.
The canned ones have issues, too. While cooking softens the exoskeleton (which is a plus), it also breaks down some nutrients. Canned bugs smell different enough that many pets won’t touch them. The upside of buying cans of mealworms is that they last for a long time on a shelf, are easy to serve, and there is no risk of escape.
Dead mealworms are better than nothing, but they should supplement and not replace live feeders.
Buying & Storing
Price range
Live mealworms are inexpensive.
Many big chain pet stores’ prices start around $0.06 each for a 50-count container and drop by a penny a worm for a 100-count tub. The quality of these cups varies, too. Some have a lot of dead (unusable) mealworms in them, driving the “price per insect” up.
Online retailers sell boxes with more mealworms at a much lower cost per worm. A 500-count of medium-sized larvae sells for $0.02 each, plus shipping.
This model is similar to crickets, but mealworms can be refrigerated to last longer, making bulk purchases work better for most keepers.
Where should I buy them?
Live mealworms are widely available, so you have options. But which are the best? We want healthy mealworms that live long enough to be eaten by your pet.
Your local pet store is probably your best option when you only need a few. While they are more costly per worm, you will likely spend less avoiding shipping. A smaller container also makes it less likely that you will overfeed them.
Online sellers are a great option if you can’t find mealworms near you or if you have pets who go through a lot of them quickly.
How do I keep them?
Small orders of mealworms come in plastic cups filled with bedding that doubles as their food. You can keep them in this container. Larger counts need more space and a cover with mesh or a screen for air to flow in and out. The media should be two-to-four inches deep.
Since the nutrients they will pass along to your pet are based on what they eat, the food for the mealworms is worth noting. Any high-quality powdered grain mix will work well. You can choose between store-bought premade food or making it at home by blending a variety of cereals and grains.
Mealworms get their hydration by eating fruits and vegetables, most often carrots and potatoes. Remove leftovers once they have dried out to avoid mold.
As mealworms eat, they leave behind waste (or frass) and shed skins. While this will build up over time, it doesn’t seem to bother the worms. Pay attention to the media and add food as needed.
Mealworms kept at room temperature last around three weeks. They can be refrigerated to keep them dormant, extending their lifespan to 2-3 months. While they are at 45-50 degrees Fahrenheit, everything slows down for them; they will move, eat, poop, and grow less.
If you are storing your mealworms in the fridge, keep them at room temperature for 24 hours once every seven days. While they are out, add a piece of apple, carrot, or sweet potato. The temperature change and food help extend their lifespan and maintain their nutritional value.
How long do they live?
Mealworms stay in the larval stage for 3-4 weeks at room temperature or for months if refrigerated properly.
Do All Crested Geckos Like Mealworms?
Just like with humans, each crested gecko has preferences. Not every person wants the same foods, nor does every crestie.
Mealworms are an ‘acquired taste’ for crested geckos. Most do not readily feed on them, but some adults learn to eat them.
Conclusion
The crested gecko community is not of one opinion on mealworms, and there is limited peer-reviewed research to back up the “right answer.” All the pros and cons of mealworms and crested geckos are here for your review.
We are not feeding our crested geckos mealworms at this time. With all the other live insects to choose from, there isn’t a good reason to use them.
What about other insects? Can Crested Geckos Eat Waxworms?
References
- Caponetto, A. (n.d.). Crested gecko myths. Retrieved January 27, 2023, from https://acreptiles.com/new_store/index.php?dispatch=pages.view&page_id=38
- Finke, M. D. (2014). Nutritional value of commercially-raised insects. Retrieved January 27, 2023, from https://geckotime.com/nutritional-value-of-commercially-raised-insects/
- Healey, M. (n.d.) Crested gecko food. Retrieved January 27, 2023, from https://reptifiles.com/crested-gecko-care/crested-gecko-food/