Mealworms vs. Roaches: Which Feeder Is Better, and How Much to Feed

This is the feeder question I get asked more than almost any other: mealworms or roaches — which is better, and how much do I actually feed? It comes up because both are everywhere, both are cheap enough, and the marketing around each one is confident and contradictory. So let me give you the straight version from years of keeping feeders and feeding them off: roaches are the better staple, mealworms are a fine occasional feeder, and the "how much" answer is more about size and frequency than about counting worms.

This guide does two things. First, it compares mealworms and roaches honestly — real nutrition, real digestibility, real trade-offs, with the common myths corrected (including the big one about roaches having a "perfect" calcium ratio, which they don't). Second, it gives you concrete feeding amounts: how to size a feeder, how often to feed by life stage, how much per session, and specific guidance by animal. By the end you'll know exactly what to build the diet on and how much to put in the bowl.

Meet the two feeders

Mealworms (Tenebrio molitor)

Mealworms are the larval stage of the darkling beetle, Tenebrio molitor. They're the smooth, tan, segmented "worms" you've seen in every pet store — except they aren't worms at all, they're beetle larvae. Their defining physical trait as a feeder is a firm, chitinous exoskeleton. That shell is harder than people expect for something that looks soft, and it's the root of mealworms' biggest downside: chitin is difficult for many reptiles and amphibians to digest, and in smaller animals it's an impaction risk.

Their selling points are real: mealworms are cheap, available everywhere, and dead easy to keep. You can hold them in a cool spot to slow their development for weeks, they barely smell, and most animals find their wiggling irresistible. As a convenience feeder they're hard to beat.

A note on storage, since the source advice on this gets repeated badly: people often say to refrigerate mealworms at around 40°F. That cold storage does slow them down, but at true fridge temperatures it stresses and slowly kills them over time. A cool spot in the upper 40s to mid-50s holds them far better and longer than the back of a cold refrigerator.

Roaches (Blaberus discoidalis and Blaptica dubia)

The two feeder roaches you'll actually encounter are discoid roaches (Blaberus discoidalis) and dubia roaches (Blaptica dubia). They're close cousins and, for feeding purposes, nearly interchangeable. Both are flat, oval, slow-moving roaches that cannot climb smooth vertical surfaces like glass or smooth plastic — which makes them dramatically easier to contain than crickets — and both have a soft, low-chitin body that's much easier to digest than a mealworm's.

The one real difference that matters to you is legal, not nutritional: dubia roaches are restricted in Florida, where discoids are the accepted, widely kept feeder. If you're in Florida, that decision is made for you. Everywhere else, pick on price and availability — they perform the same in your animal.

Both species breed readily in a bin at home, which is the other reason serious keepers love them: you can own your staple feeder supply instead of buying it weekly. If you want to do that, I've written the complete discoid roach breeding playbook covering enclosure, heat, humidity, and harvesting.

A word on superworms (so you don't confuse them with mealworms)

People often lump superworms in with mealworms because they look like bigger versions of the same thing. They're not the same species — superworms are the larvae of Zophobas morio, a different darkling beetle — and nutritionally they're even fattier than mealworms (often ~15% fat), with a hard head capsule. Everything this guide says about mealworms being a treat-not-staple goes double for superworms: great occasional feeders for larger animals, poor everyday base. If you're choosing between mealworms and superworms for a staple, the answer is "neither — use roaches."

The nutrition, honestly

Here's where the marketing and the biology diverge, so let me lay out the numbers plainly. Treat these as approximate, as-fed ranges — actual values shift with diet, life stage, and source — but the relationships between feeders are reliable, and the relationships are what should drive your decisions.

Protein

Both feeders deliver real protein, but roaches edge mealworms out, and the quality of that protein matters more because it isn't wrapped in as much fat or armor. Dubia and discoids land around 20% protein; mealworms sit a bit lower at roughly 18–20%. For a growing juvenile that needs protein for muscle and bone, the roach is doing more useful work per feeder.

Fat — the real divider

This is the single biggest nutritional difference. Mealworms are fatty — commonly in the 13–15% fat range — while roaches run leaner, around 7–9%. That gap is exactly why mealworms cause obesity and fatty-liver disease when they become the everyday diet, especially in sedentary adult animals. The fat makes mealworms great for the occasional energy boost and useless as a daily base. Roaches' lower fat is what lets them carry the staple role without packing weight on your animal.

Calcium — and the myth you need to drop

Here's the correction that matters most. You will read — including in older versions of this very article's source — that roaches have a "favorable" or "1:1" calcium-to-phosphorus ratio and therefore don't really need supplementation. That's wrong. Like nearly every feeder insect, roaches are phosphorus-heavy and short on calcium. They are less bad than mealworms (whose ratio is dismal, roughly 1:15), but "less bad" is not "good," and it is not "skip the calcium."

The practical rule is simple and applies to both feeders: dust with a calcium supplement before feeding. The only common feeder that's genuinely calcium-rich by nature is black soldier fly larvae (BSFL) — every other staple, roaches included, needs calcium dusting to prevent metabolic bone disease. If you take nothing else from this section, take that: roaches are the better staple, and you still dust them with calcium.

Moisture and digestibility

Roaches carry more moisture (~60–70%) than mealworms (~50–55%), which helps hydration a little, especially for animals that drink mostly through their food. But the bigger digestibility story is chitin. A mealworm's hard exoskeleton is genuinely tougher on a reptile's gut, and in juveniles and small geckos it's an impaction risk. A roach's soft body passes far more easily. For a young, small, or sensitive animal, that softness alone is a strong argument for roaches.

The verdict: roaches as staple, mealworms as treat

Putting it together:

• ◆Roaches win as the everyday staple — more usable protein, much less fat, soft and easy to digest, and (for discoids especially) legal where dubia aren't. Build the diet on them.
• ◆Mealworms are a fine occasional feeder — cheap, available, palatable, and a useful energy boost — but their fat and hard chitin disqualify them as a base. Rotate them in; don't lean on them.
• ◆Both still need calcium dusting. Neither is a "perfect ratio" feeder. The roach's edge is leaner fat and softer body, not a free pass on supplementation.

The healthiest setup most keepers can run is a roach-based staple with variety rotated in — mealworms occasionally, plus hydration/treat feeders like hornworms and naturally calcium-rich BSFL — all dusted with calcium on your species' schedule. When you're sourcing the staple, All Angles Creatures stocks discoid roaches sized for everything from small geckos to adult dragons, which is the easiest way to make roaches your base.

Gut-loading: the feeder's diet becomes your animal's diet

Whichever feeder you use, what the insect ate in the last day or two is what your animal actually eats. A starved feeder is a hollow calorie; a well-fed one delivers real nutrition. This is gut-loading, and it's the cheapest upgrade to feeder quality there is.

The protocol is simple: for 24–48 hours before you feed off, give the feeders nutrient-dense food. Good gut-load includes fresh vegetables and greens (carrot, squash, sweet potato, collard and mustard greens, dandelion), small amounts of fruit (apple), and a quality dry feeder chow as a steady base. Then feed the insects to your animal while that nutrition is still in their gut.

A few cautions that apply to both mealworms and roaches: avoid anything high in oxalates (spinach binds calcium and works against you), skip salty, oily, or processed foods, go easy on heavy citrus, and never use produce that might carry pesticides — wash everything. Gut-loading does not replace calcium dusting; the two do different jobs. Gut-loading enriches the feeder's overall nutrition; dusting coats the outside with the calcium the feeder itself can't provide in the right ratio.

Supplementation: dusting done right

Because neither feeder carries enough calcium, supplementation is where you actually prevent metabolic bone disease — the single most common nutritional disease in captive insectivores. Here's the practical scheme most keepers run, adjusted to your specific species:

• ◆Plain calcium (no D3): the workhorse, used on most feedings. It corrects the phosphorus-heavy ratio of the feeder.
• ◆Calcium with D3: used less often, on a schedule, for animals that don't get strong UVB exposure (D3 lets them actually use the calcium). Animals under good UVB lighting make their own D3 and need this less; over-supplementing D3 can cause its own problems, so this one is scheduled, not every meal.
• ◆Multivitamin: a light dusting on an occasional schedule (often weekly or so) to cover trace vitamins and minerals, including vitamin A where the species needs it.

The exact frequency varies by species, age, and lighting — a juvenile under marginal UVB needs more calcium support than a well-lit adult — so match the schedule to your animal. But the universal rule stands: dust feeders with calcium, every time, for both mealworms and roaches. "The roach has a good ratio" is not a reason to skip it.

How much to feed: the part everyone gets wrong

"How much" almost never has a single number answer, because the right amount depends on the animal's species, age, size, and activity level. But there are reliable rules. Here's how to actually decide.

Rule 1: Size the feeder correctly

Before quantity, get the size right — this is the safety rule. Feed insects no longer than the space between the animal's eyes. That's a slightly more conservative version of the old "no bigger than the head" guideline, and it's the right one to use because oversized prey is the leading cause of choking, regurgitation, and impaction — especially with a hard-shelled mealworm and especially in juveniles and small geckos. When in doubt, drop a size and pick the softer feeder.

This is also where roaches shine: they come in a continuous range of nymph sizes, so you can always match the exact size your animal needs, from pinhead nymphs for hatchlings up to adults for big dragons and monitors.

Rule 2: Match frequency to life stage

Age drives how often you feed far more than how much per meal:

• ◆Hatchlings and juveniles are in rapid growth and need protein often — typically daily, sometimes multiple short sessions a day for fast growers like baby bearded dragons.
• ◆Adults have slower metabolisms and need far less. Depending on species, that's anywhere from every other day to a couple of times a week. Overfeeding adults is the single most common husbandry mistake and the usual road to obesity.

Rule 3: Use the 10–15 minute window

For many insectivores, the most reliable portion method isn't counting worms — it's the clock. Offer appropriately sized, dusted feeders and let the animal eat as many as it wants in about 10–15 minutes, then remove the leftovers. This self-regulates to the animal's appetite and activity level, and pulling uneaten insects keeps them from stressing or nibbling the animal overnight. For animals where exact counts make more sense (small geckos), a typical session is a few feeders — often in the 3–10 range depending on size.

Rule 4: Watch the animal, not just the chart

Body condition is the final arbiter. Adjust down if you see fat pads building, a thickening tail base, lethargy, or refused meals (signs of overfeeding); adjust up if you see weight loss, a thin tail, sunken eyes, or sluggishness from too little (signs of underfeeding). The schedule is a starting point; the animal's body tells you whether it's right.

How much to feed, by animal

Here's concrete, species-specific guidance built on the rules above. In every case: size the feeder to the eye-gap, dust with calcium, and remove leftovers.

Bearded dragons

Classic omnivore that flips diet with age. Juveniles are protein machines — offer appropriately sized roach nymphs (and the occasional mealworm) multiple times a day, as many as eaten in a 10–15 minute window, alongside finely chopped greens. Adults shift heavily toward greens; a smaller portion of insects every 2–3 days is typical. This is the species most damaged by a mealworm-heavy diet — keep mealworms occasional and the staple roach-based to avoid obesity.

Leopard geckos

Pure insectivore, so insects are the whole diet. Feed small-to-medium roach nymphs sized to no longer than the gap between the eyes. Juveniles daily; adults every 2–3 days, a few feeders per session (commonly 3–6 appropriately sized), dusted with calcium. Leopard geckos are a prime example of why the staple should be soft roaches rather than hard mealworms — impaction risk is real in this species, and a mealworm-only diet is a frequent cause of poor health.

Crested geckos

These thrive primarily on a complete commercial crested-gecko diet, with insects as a supplement and enrichment rather than the base. Offer small roach nymphs once or twice a week, dusted, for extra protein and hunting stimulation. Mealworms can appear in the rotation but aren't necessary.

Larger frogs and toads (Pacman frogs, large toads)

Big-appetite ambush feeders that will overeat if you let them. Offer adult roaches and large nymphs every few days for adults, more often for juveniles, and watch body condition closely — these animals get obese readily. Soft-bodied roaches are easier on them than hard mealworms.

Monitors, tegus, and larger lizards

For larger carnivores and omnivores, feeder insects are part of a varied diet that also includes whole prey and other proteins rather than the entire meal. Adult roaches are the practical insect component; mealworms are too small and too fatty to be a meaningful staple for animals this size.

Small skinks and other small insectivores

For obesity-prone species like some skinks, lean hard on the leaner roach and limit fatty mealworms. Size down the feeders, feed juveniles more often than adults, and keep calcium dusting consistent.

Keeping each feeder alive at home

How you store the feeder between deliveries affects its quality as much as its species does.

Mealworms are the low-effort feeder. Keep them in a ventilated container with a substrate of wheat bran or rolled oats — which doubles as their food — plus a slice of carrot or potato for moisture (replaced before it molds). To slow their development and stretch a batch, hold them in a cool spot. The common advice to refrigerate them at ~40°F does slow them, but true fridge cold stresses and slowly kills them; the upper 40s to mid-50s holds them far better and longer. Warm them back up periodically if you're storing them cold, and pull any dead or darkened larvae. Left warm, mealworms pupate into white pupae and then darkling beetles — not a failure if you want to breed them, but the end of their feeder window.

Roaches want the opposite: warmth. A discoid or dubia colony breeds in the mid-80s to 90°F with moderate humidity, vertical egg-flats for surface area, a dry protein-based chow, and rotated produce for moisture and gut-loading. They don't climb smooth bins, they barely smell, and a properly set-up colony essentially runs itself and supplies your staple indefinitely. The full build — enclosure, side-mounted heat on a thermostat, humidity, harvesting, and troubleshooting — is in my discoid roach playbook. The headline reason to breed your own: it turns the staple from a recurring purchase into a one-time setup.

The mealworm life cycle, and why it matters

It's worth knowing what a mealworm is becoming, because it affects storage and breeding. A mealworm is a larva on its way to being a darkling beetle: egg → larva (the feeder) → pupa → adult beetle. Held warm, the larva pupates into a pale, comma-shaped pupa that doesn't move much, then darkens into a beetle. None of the non-larval stages are great feeders — pupae are inert and beetles are hard and produce defensive compounds many animals dislike — so the larva is the stage you want, and cool storage is how you hold it there longer. If you do want to breed mealworms (it's cheap and easy), you let some reach beetle stage in a bin of bran; the beetles lay eggs that become your next generation. Roaches, by contrast, are live-bearing and stay in usable form across all their nymph sizes, which is part of why they're a more flexible feeder supply.

Live vs. dried, canned, and freeze-dried mealworms

You'll see mealworms sold not just live but dried, freeze-dried, and canned. A few honest notes:

• ◆Live is best for most reptiles and amphibians. The movement triggers prey drive, and the nutrition is intact.
• ◆Canned/cooked mealworms can work for animals that accept non-moving prey, but you lose the motion that stimulates feeding and some nutritional value.
• ◆Dried/freeze-dried mealworms are convenient and shelf-stable but are the least nutritious form and, critically, very dry — feeding a lot of dried insects without addressing hydration is a real risk for some species. They're more appropriate as an occasional supplement (and they're popular for chickens and wild birds) than as a reptile's main feeder.

For a healthy captive reptile, live feeders — roaches as the staple — are the standard, and processed mealworms are a convenience item, not a substitute.

Mealworms for other animals

Mealworms aren't only a reptile feeder, and it's worth knowing the wider context since you'll see them marketed broadly. Backyard chickens love them as a high-protein treat (in moderation — they're rich), wild and pet birds take them readily (especially bluebirds and during breeding season), and they're used for fish, hedgehogs, and other insectivorous pets. The same principles travel: they're a fatty, protein-decent treat rather than a complete diet, and portion control matters because animals will gorge on them. For your reptile specifically, none of that changes the core verdict — roaches make the better staple, mealworms the better occasional treat.

The economics, briefly

People often pick mealworms because they're cheaper per insect up front. That's true at the pet-store level, but it's the wrong frame. The real cost of a feeder includes the vet bills and shortened lifespan that come from an obese, calcium-starved animal on a mealworm-only diet — and those dwarf the price difference. Roaches cost a bit more per bug retail, but if you breed your own colony the per-insect cost drops to nearly nothing and you never run out. The cheapest healthy option over an animal's life is almost always a home roach colony with mealworms bought occasionally as variety.

Switching a mealworm-addicted animal to roaches

If you inherited or started an animal that only wants mealworms, you can transition it — animals get fixated on a familiar food, but it's rarely permanent. Tactics that work:

• ◆Offer roaches first, when the animal is hungriest, before any mealworms appear.
• ◆Make the roach move. Prey drive is triggered by motion; a wiggling roach nymph in front of a hungry animal is hard to resist. Tongs or a shallow dish with active feeders helps.
• ◆Don't cave too fast. A healthy adult can skip a meal or two without harm while it learns; persistence usually wins within a week or two. (Juveniles and small species have less reserve — go gentler and consult a vet if an animal genuinely refuses food for an extended stretch.)
• ◆Phase mealworms down, mixing fewer in over time rather than cutting them cold, until roaches are the base and mealworms are the occasional treat.

Impaction: the risk you're managing

A lot of the "which feeder, how much, what size" advice ultimately comes back to impaction — a blockage in the digestive tract that can be serious or fatal. Hard-shelled feeders (large mealworms, superworms) and oversized prey are the usual triggers, and juveniles and small geckos are most vulnerable. Warning signs include a swollen belly, straining without passing stool, loss of appetite, and lethargy. Prevention is exactly the rule set above: soft-bodied roaches as the staple, feeders sized to the eye-gap, appropriate enclosure temperatures for digestion, and not overfeeding hard mealworms. If you suspect an impaction, that's a vet visit, not a home fix.

Where the other feeders fit around the roach staple

Mealworms versus roaches is the core question, but neither is the whole answer — the best diets rotate a few feeders around a roach base. Quick orientation on the supporting cast so you know how to build the rotation:

• ◆Crickets are the other classic staple. Nutritionally they're decent (moderate protein, higher chitin than roaches), but they're loud, they smell, they jump and escape, and they die easily — which is exactly why so many keepers move to roaches. If you like crickets, they work as a staple alongside roaches; just know roaches are the lower-hassle option.
• ◆Hornworms are nearly all water (~85% moisture) with low fat — a fantastic hydration treat and a great way to get fluids into an animal, but far too low in protein to carry a diet. Rotate them in occasionally, especially for an animal that needs a hydration boost.
• ◆Black soldier fly larvae (BSFL), also sold as Calci-worms or Phoenix worms, are the one feeder that's naturally calcium-rich — the exception to the dust-everything rule. They make an excellent rotation feeder precisely because they fix the calcium gap the others have. Small and soft, good for many species.
• ◆Waxworms are the high-fat treat — great for putting weight on a thin or recovering animal, terrible as a daily food. I cover keeping them alive in the waxworm shipping and storage guide.

The healthiest pattern: roach staple, BSFL for calcium variety, hornworms for hydration, and mealworms/waxworms as occasional treats — all dusted (except BSFL, which you can dust less aggressively) and all gut-loaded.

Reading body condition

The feeding charts give you a starting point; your animal's body tells you whether you've got it right. Learn to read it and you'll never need a calculator.

Signs you're overfeeding (cut back frequency, swap fatty feeders for leaner roaches): visible fat pads — often a bulging tail base in geckos or fat deposits behind the front legs and around the abdomen in dragons; a generally chunky, rounded look; lethargy and reluctance to move; trouble shedding; and, paradoxically, a falling appetite after prolonged overindulgence. Long-term overfeeding, especially on mealworms, drives fatty liver disease, which is hard to reverse.

Signs you're underfeeding (feed more often or more per session): visible weight loss with bones showing through; a thin, shrunken tail (geckos store fat there, so a skinny tail is an early warning); sunken eyes and wrinkled skin from dehydration; low energy; stunted growth in juveniles; and behavior changes like irritability or excessive hiding.

Weigh adult animals periodically on a small kitchen scale and track the trend — a steady weight in a healthy range beats any feeding formula, and it catches problems before they show visually.

A simple feeding cheat sheet

Pulling the "how much" rules into one place you can act on:

Across every row: size the feeder to the eye-gap, dust with calcium, remove leftovers, and adjust by body condition.

Feeding mistakes to avoid

These are the errors I see again and again, and every one of them is preventable.

• ◆Relying on a single feeder. A mealworm-only (or even roach-only) diet drifts toward deficiency. Rotate feeders and dust with calcium.
• ◆Skipping calcium because "roaches have a good ratio." They don't — covered above. Dust both feeders.
• ◆Feeding oversized prey. The eye-gap rule exists to prevent choking and impaction. Respect it, especially with hard mealworms and small animals.
• ◆Leaving uneaten insects in the enclosure. Mealworms burrow and hide; loose feeders can nibble or stress your animal overnight. Remove leftovers after the feeding window.
• ◆Skipping gut-loading. Feed your feeders well for 24–48 hours before offering them — fresh greens, squash, carrot, and a quality dry feed. The feeder's diet becomes your animal's diet one step removed.
• ◆Overfeeding adults. Slower metabolism, same enthusiasm — adults get fat fast. Stretch the frequency and watch body condition.
• ◆Storing feeders too cold. Both mealworms and roaches do better in a cool spot (upper 40s to 50s for mealworms; roaches want warmth to breed but tolerate cool holding) than jammed in a 40°F fridge that slowly kills them.

The short version

Make roaches your staple — discoids or dubia, chosen on legality (discoids in Florida) — because they're higher in usable protein, much leaner, and far easier to digest than mealworms. Keep mealworms as an occasional feeder, not the base; their fat and hard chitin make a mealworm-only diet a path to obesity and impaction. Dust everything with calcium — neither feeder has the "perfect ratio" myth claims; only black soldier fly larvae are naturally calcium-rich. For amounts: size feeders to the eye-gap, feed juveniles daily and adults every 2–3 days (or per species), let them eat for 10–15 minutes, remove leftovers, and adjust by watching body condition. Do that and you've solved both halves of the question — which feeder, and how much.

For the underlying nutrient data behind these comparisons, see Mark Finke's peer-reviewed analysis of feeder-insect composition (Finke, Zoo Biology, 2002, doi:10.1002/zoo.10031) and the MSD/Merck Veterinary Manual on reptile nutrition.

Building your feeder supply? Read the full discoid roach breeding playbook, learn how to keep treat feeders alive in my waxworm shipping and storage guide, or browse the complete feeder insect care library.