Discoid Roaches vs. Silkworms for Bearded Dragons: A Keeper's Feeding Guide
People ask me to pick a winner between discoid roaches and silkworms all the time, and every time I have to gently reframe the question. These two feeders aren't competing for the same job. A discoid roach is a workhorse staple — the bug you build a diet around. A silkworm is a premium specialty feeder — the bug you reach for when you want low fat, easy digestion, hydration, and a calcium-friendly profile. Asking which is "better" is like asking whether a truck is better than an ambulance. It depends entirely on what you need it to do.
I've fed both for years, bred discoids by the thousands, and bought silkworms by the cup whenever I had a hatchling clutch or a dragon coming off illness. This guide lays out exactly what each one offers — with the real nutrition numbers and the common myths corrected — so you can stop thinking in terms of winner-takes-all and start using both intelligently.
The two feeders at a glance
Before the deep dive, here's the honest one-paragraph version. Discoid roaches (Blaberus discoidalis) are high in protein, moderate in fat, soft and easy to digest, hardy, nearly odorless, come in every size, and breed at home — making them an outstanding staple. Silkworms (Bombyx mori) are very low in fat, soft-bodied, hydrating, and relatively higher in calcium than most insects — making them an excellent treat and a standout choice for hatchlings, gravid females, and recovering dragons. The smart move is to use roaches as the foundation and silkworms as the high-value supplement.
| Factor | Discoid roach | Silkworm |
|---|---|---|
| Scientific name | Blaberus discoidalis | Bombyx mori |
| Protein (as fed) | High (~20%) | Low–moderate (~9–13%) |
| Fat (as fed) | Moderate (~6–8%) | Very low (~1–3%) |
| Moisture | ~60–65% | High (~76–83%) |
| Calcium:phosphorus | Poor (phosphorus-heavy) — dust | ~1:1 or slightly better — still dust |
| Exoskeleton | Soft, low chitin — easy to digest | None to speak of — very easy |
| Movement | Steady crawl | Slow, gentle |
| Keeping difficulty | Easy; breeds readily | Fussy; short-lived |
| Best role | Staple | Treat / hydration / juveniles |
What discoid roaches bring to the table
Discoid roaches are a tropical species native to Central and South America, widely bred as feeders. They're flightless, they can't climb smooth surfaces, they're quiet, and they barely smell — practical traits that make them painless to keep indoors.
Nutritionally, their case is strong:
- High, digestible protein (~20%) — the muscle-building macronutrient juveniles need and adults still benefit from in moderation.
- Moderate fat (~6–8%) — enough energy without the obesity risk of fatty feeders like superworms.
- A soft, low-chitin exoskeleton. This is the point most sources get backwards. Roaches have less chitin than crickets or mealworms, which makes them notably easier to digest and lowers impaction risk — especially for younger dragons.
- Useful moisture (~60–65%) that contributes to hydration.
They also gut-load beautifully — feed the roaches well for a day or two and that nutrition transfers straight to your dragon — and they come in a continuous size range from pinhead nymph to two-inch adult, so a single source covers a dragon's whole life.
The one honest caveat, and it applies to almost every feeder: discoid roaches are phosphorus-heavy. Their natural calcium-to-phosphorus ratio is poor, which is why you'll dust them with calcium before feeding. Don't believe the widespread claim that roaches have a "favorable" calcium ratio — they don't. Their advantages are protein, digestibility, and ease of keeping, not calcium.
What silkworms bring to the table
Silkworms are the larvae of the domestic silk moth, raised for millennia on mulberry leaves. As a feeder they have a distinctive, almost opposite profile to roaches:
- Very low fat (~1–3%). Among the leanest feeders available, which makes them ideal for keeping a dragon from gaining excess weight.
- A soft, exoskeleton-free body. Nothing crunchy, nothing hard to digest — about as gentle on the gut as a feeder gets, which is why they're so good for hatchlings and sick dragons.
- High moisture (~76–83%). Real hydration value, especially for a dragon that doesn't drink readily.
- A relatively good calcium-to-phosphorus ratio — roughly 1:1 or slightly calcium-favorable. That's genuinely better than most insects, which lean phosphorus-heavy. It's still below the ~2:1 dietary target for dragons, so I dust silkworms too, but they need less help than most.
The honest limitation is protein. Fresh silkworms are lower in protein than roaches, so as nourishing and digestible as they are, they can't be the only protein source. They're a superb supplement, not a backbone.
Head-to-head: nutrition
Lining the two up directly:
- Protein: Discoid roaches win clearly. For growth and muscle, roaches deliver more protein per feeder.
- Fat: Silkworms win for leanness. If you're managing weight, silkworms are the safer frequent feeder.
- Hydration: Silkworms win, and it's not close — they're mostly water versus the roach's moderate moisture.
- Calcium balance: Silkworms win on their natural ratio, but both get dusted — roaches always, silkworms as insurance.
- Digestibility: Effectively a tie, both excellent — silkworms have no shell, roaches have a soft low-chitin one. Both are far gentler than crickets or mealworms.
The takeaway: roaches are the better nutritional engine; silkworms are the better gentle, hydrating, lean feeder. Different strengths, both real.
Head-to-head: behavior and feeding response
Bearded dragons are visual hunters that respond to movement, so how a feeder moves matters.
Discoid roaches crawl in a steady, deliberate way. That's easy for juveniles and less-experienced dragons to track and catch, and roaches' tendency to scuttle and hide can encourage natural foraging. The flip side is that a stationary roach sometimes fails to trigger a very stimulated dragon.
Silkworms move slowly and gently. That makes them perfect for older, lethargic, or recovering dragons that can't or won't chase fast prey, and dead-easy for tiny hatchlings. The trade-off is that their low-key movement may not excite a healthy, hungry adult the way a scuttling roach does.
In practice, most dragons happily eat both. If you have a picky or under-motivated eater, the roach's movement is often the better trigger; if you have a delicate or recovering one, the silkworm's gentleness is the better fit.
Head-to-head: keeping and care
This is where the two diverge the most.
Discoid roaches are easy. A warm, ventilated bin with egg flats, a dish of dry food, some produce, and a water-crystal source is all they need. They're hardy, long-lived, nearly odorless, and they breed readily — females give live birth, so there are no fragile egg cases to manage. A modest starter colony can become a self-sustaining feeder supply, which is a real money-saver for a multi-reptile household. (For the full setup, see my discoid roach keeping and breeding playbook.)
Silkworms are fussy. They depend on mulberry leaves or commercial silkworm chow, both of which can be a hassle to source. They're sensitive to temperature and humidity — they want warmth around the mid-70s to mid-80s °F and clean, not-too-damp conditions — and they're delicate enough that rough handling kills them. Worst of all for the keeper, they have a short life cycle of just a few weeks before pupating into moths, at which point they're useless as feeders. That's why almost everyone buys silkworms as needed rather than trying to maintain a long-term supply.
Bottom line: roaches are a standing colony you barely think about; silkworms are a perishable specialty purchase.
Head-to-head: cost and availability
Per feeder, silkworms are usually more expensive — they're labor-intensive to raise, perishable, and depend on a specialized diet. Their availability can be seasonal too.
Discoid roaches are more economical, especially in bulk or if you breed your own, and they're widely available year-round from feeder suppliers. They're also the legal roach staple in places like Florida where dubia roaches are restricted, which broadens their availability further.
For a keeper feeding daily, the math strongly favors roaches as the staple and silkworms as the occasional premium add-on.
How to feed discoid roaches properly
- Choose healthy roaches — active, glossy, no deformities. Buy from a clean source.
- Gut-load for 24–48 hours with leafy greens, carrots, squash, and a dry roach chow. Skip anything toxic (avocado, onion, citrus-heavy items).
- Dust with calcium before feeding — plain calcium most feedings, calcium/D3 or multivitamin on a lighter schedule matched to your UVB.
- Size to the eye-gap rule: no roach wider than the space between your dragon's eyes. Small nymphs for babies; larger nymphs and adults for grown dragons.
- Feed in a window (~10–15 minutes), then remove uneaten roaches so they don't stress or nip the dragon overnight.
How to feed silkworms properly
- Pick healthy worms — plump, pale, smooth, active. Discard any discolored or off-smelling ones.
- Gut-load if you're keeping them more than a day, using silkworm chow or fresh mulberry; this maintains their value.
- Size to the eye-gap rule and offer the smaller worms to juveniles.
- Serve in a shallow dish so the slow-moving worms don't wander off and stay easy for the dragon to grab.
- Dust with calcium as insurance even though their natural ratio is decent.
- Supervise and clean up — remove uneaten worms promptly so they don't spoil in the enclosure.
The real answer: use both
The healthiest diets I've raised dragons on don't pick a side. Discoid roaches form the protein backbone — the everyday staple that drives growth and muscle. Silkworms rotate in as the lean, hydrating, calcium-friendly change of pace, and they shine for specific dragons and moments:
- Hatchlings and juveniles: silkworms' softness and digestibility make them a safe, valuable protein source alongside small roach nymphs.
- Gravid (egg-carrying) females: the extra calcium and easy digestion help.
- Recovering, dehydrated, or picky dragons: silkworms' moisture and gentleness are exactly what's needed.
- Weight-conscious adults: silkworms' near-zero fat lets you offer a protein-ish treat without the fat load.
Alternating the two across the week also prevents dietary monotony and keeps mealtimes engaging. Round it out with leafy greens and the occasional other feeder, dust appropriately, and you've got a genuinely complete plan.
When you're stocking up, All Angles Creatures carries discoid roaches in colony and feeder sizes so you can keep a steady staple supply on hand and add silkworms when a clutch or a recovering dragon calls for them.
Common mistakes to avoid
- Treating silkworms as a staple. They're too low in protein to carry the diet alone, no matter how nutritious they are otherwise.
- Skipping calcium on roaches. They're phosphorus-heavy — dusting is mandatory, not optional.
- Feeding too big. The eye-gap rule applies to both feeders.
- Letting silkworms pupate. Buy what you'll use; they have a short window.
- Leaving uneaten roaches in the tank overnight. Remove them.
- Relying on one feeder. Even a great staple alone leaves gaps — rotate.
The short version
Discoid roaches are the staple; silkworms are the specialist. Roaches give you high protein, easy digestion, and a self-sustaining home supply — dust them with calcium every time because they're phosphorus-heavy. Silkworms give you very low fat, real hydration, a soft body that's perfect for babies and recovering dragons, and the best natural calcium ratio of the two — though you'll still dust them as insurance. Build the diet on roaches, rotate silkworms in for variety, hydration, and your most delicate dragons, and you get the best of both instead of forcing a choice that was never really a choice.
Keep comparing: see silkworms vs. discoid roaches from the silkworm's angle and the broader guide to choosing the best feeder, or browse the full exotic animal care library.