Silkworms vs. Discoid Roaches for Blue Tongue Skinks: Which Feeder Wins?

Blue tongue skinks are omnivores with a genuinely mixed diet, and the protein half of that diet is where the silkworm-versus-discoid-roach question comes up. I've fed both to skinks for years, and the short answer is that they're not really competitors — they're complementary tools. But if you only want to keep one going at home, the trade-offs matter, so here's the honest head-to-head.

What a blue tongue skink actually needs

Before picking a feeder, anchor on the diet. Blue tongues do best on roughly half vegetables (dark leafy greens like collard, mustard, and dandelion, plus some squash and other low-oxalate veg), a solid share of protein, and only a small fraction of fruit as a treat. Insects cover the protein portion, and the cardinal rule is variety — over-relying on a single feeder invites nutritional gaps. So the real question isn't "silkworms or discoids forever," it's "which one anchors my rotation, and which one rounds it out."

Nutrition head-to-head

Discoid roaches are a high-protein, moderate-fat, soft-bodied feeder. As fed, they run roughly 20–25% protein, around 5–8% fat, and 65–70% moisture, with a low chitin content that makes them easy to digest. They're a near-ideal staple insect for a skink: filling, nutritious, and gentle on the gut.

Silkworms are softer still and leaner. On a dry-matter basis they're very high in protein (often cited around 60%+ dry), but they're also very high in moisture — about 85% of their body weight is water — and low in fat. That high water content makes them a good hydration boost and an easy chew for juveniles or any skink with jaw or dental trouble.

The one claim I'll correct: you'll read that both feeders have a "favorable" calcium-to-phosphorus ratio. Treat that with skepticism. Nearly every feeder insect is phosphorus-heavy, and the safe assumption is that you dust with calcium regardless. Gut-loading improves what's inside the feeder, but it doesn't fix the calcium gap — dusting does.

Here's the practical comparison:

Digestibility and impaction

For a blue tongue, digestibility is a real consideration, and both feeders score well here for different reasons. Silkworms have no hard exoskeleton at all, so they're about as easy to digest as a feeder insect gets — which is precisely why they shine for juveniles, very small skinks, or any animal with jaw or dental limitations. Discoid roaches are soft-bodied with low chitin, far gentler than crickets or mealworms, so impaction risk is low even though they do have an exoskeleton. The small amount of chitin they carry actually provides a bit of healthy fiber for gut motility. The upshot: for a tiny or compromised skink, silkworms are the safer first choice; for a healthy adult, discoids are perfectly digestible and bring more substance per feeder.

Ease of keeping and cost

This is where discoids pull ahead for most keepers. Discoid roaches are hardy and easy to breed. A small starter colony establishes in a warm, humid bin, reproduces year-round, and within a few months runs as a near-free, self-sustaining protein supply. They're odorless, quiet, and don't climb smooth walls, so containment is simple. (Ignore sources that call discoids "excellent climbers" and an escape risk — adults can't grip smooth plastic or glass; the only real escapees are pinhead nymphs through poor ventilation.)

Silkworms are delicate and short-lived by comparison. They need clean, dry housing, consistent warmth, and a diet of mulberry leaves or commercial mulberry-based chow — which isn't always available year-round. They're prone to mold if conditions slip, grow fast, and need feeding off promptly. Most keepers buy silkworms in batches as needed rather than breeding them, which makes them the pricier, more hands-on option over time.

So: discoids win on cost, sustainability, and low maintenance; silkworms win on softness, hydration, and being foolproof to feed to a fussy skink.

Availability

Both are more specialized than crickets or mealworms, but they differ in how reliably you can get them. Discoids are available year-round and, once you have a colony, you're largely self-sufficient — a big practical advantage. Silkworms can be seasonal, since their supply is tied to mulberry availability, and they're often sold in smaller quantities live, canned, or as eggs to hatch. If a steady, predictable supply matters to you, that tilts toward discoids; if you only want occasional silkworms as a treat, buying small batches as needed is fine.

Handling, storage, and palatability

In the enclosure, discoids' active crawling triggers a skink's hunting instinct, which helps with reluctant eaters — drop them in a shallow dish so they don't scatter. Silkworms barely move, which suits skinks that prefer to graze a stationary meal; offer them with tweezers since they bruise easily. Individual skinks have preferences, so it's worth offering both early to learn what yours responds to.

For storage, discoids keep for weeks in their bin with minimal effort. Silkworms are the opposite — plan to use them within their short window and keep their habitat scrupulously clean.

Feeding schedule and how much

For a blue tongue, insects are part of the protein portion of a mixed diet, not the whole meal. Feed juveniles daily and adults about three to four times a week, with greens making up roughly half of what they eat and protein (insects plus the occasional lean meat) and a little fruit filling the rest. Size the feeders to the skink — nothing wider than the space between its eyes for younger animals — and don't let any single feeder become the default. A practical rhythm is discoids as the regular protein insect with silkworms swapped in every few feedings for variety and hydration.

Two small techniques help with both feeders. Warming a feeder slightly before offering it boosts its scent and makes it more enticing to a reluctant skink. And placement matters: drop discoids into a shallow dish so they don't scatter and hide, and offer barely-mobile silkworms by tweezers so a grazing skink finds them easily.

Risks worth knowing

Neither feeder is risky when sourced and used sensibly, but a few things are worth keeping in mind. Overfeeding protein — leaning too hard on either insect — can contribute to problems like gout in skinks over time, which is another reason to keep insects to their proper share of a mixed diet. Silkworms spoil fast, and a dead or moldy silkworm can harbor bacteria, so use them promptly and keep their housing clean. Discoid hygiene matters too: remove uneaten food, and quarantine new stock before adding it to a colony to avoid importing mites. And buy both feeders from a clean source — contaminated feeders are the main avoidable risk with any insect.

For caretakers, a minor note: some people develop sensitivities to insect proteins (silkworm "powder" or roach exoskeleton dust) and react with sneezing or itchy skin. It's uncommon, but if you're prone to allergies, handle with that in mind.

How I actually use both

My setup is simple: discoid roaches as the staple protein insect, bred at home so the cost is near zero, and silkworms rotated in as a treat — especially for juveniles, picky individuals, or any skink that needs a hydration nudge. That combination covers the protein side of a blue tongue's diet without leaning on one feeder, and it pairs with the greens that should make up the bulk of every meal.

In practice, that looks like discoids at most insect feedings, with silkworms swapped in perhaps once a week or whenever a skink is being fussy or looks like it could use the extra water. A young, growing skink leans more heavily on the protein side and gets fed more often; an adult eats insects a few times a week alongside larger portions of vegetables. Mixing in other feeders occasionally — superworms as a rare treat, the odd dubia roach — keeps the diet varied without complicating the core plan. The point is never to make any one bug the whole story.

If you're going to commit to one colony, make it discoids — they carry the diet. If you want a soft, low-fat, hydrating change-up that even a stubborn skink will take, keep silkworms on hand. Both beat crickets on smell, noise, and digestibility.

And don't lose the bigger picture in the comparison: for a blue tongue skink, the single most important dietary decision isn't silkworms versus discoids at all — it's making sure vegetables make up about half the diet, protein a solid share, and fruit only a little. Get that balance right and dust with calcium, and either feeder slots in well. The insects are the supporting cast; the greens are the lead.

When you're ready to start a colony, All Angles Creatures stocks healthy discoid roaches in mixed sizes that match juvenile through adult skinks. For the full keeping-and-breeding details, see my discoid roach playbook, and the discoid roaches 101 guide if you're new to them. For diet and metabolic-bone-disease background, the Merck Veterinary Manual's reptile nutrition section is a reliable non-commercial reference.