Silkworms for Crested Geckos: A Soft, Low-Fat Feeder Done Right

Watch a crested gecko at feeding time and you'll notice it isn't equally excited by everything. Offer a silkworm and you often get an instant lock-on: the slow, fat, pale worm wriggling in a dish is exactly the kind of soft, easy prey a crestie is wired to grab. Silkworms (Bombyx mori) are one of my favorite supplemental feeders for crested geckos — soft-bodied, low in fat, high in moisture, and gentle on digestion. The one thing to keep straight is role: silkworms are a fantastic addition to a crested gecko's diet, not the foundation of it. Here's how to use them well.

What makes silkworms a good crested gecko feeder

A few traits put silkworms near the top of the supplemental-feeder list:

• ◆Very low fat. Silkworms are one of the leanest feeders you can buy, which makes them a smart choice for a species prone to obesity when overfed fruit or fatty insects.
• ◆High moisture. Silkworms are mostly water — well over 75% — so they double as a hydration boost, useful for any gecko and especially helpful around shedding.
• ◆Soft-bodied and easy to digest. No tough chitin or hard head capsule means low impaction risk and easy eating, including for juveniles.
• ◆Decent calcium for a feeder. Most feeder insects are badly phosphorus-heavy; silkworms are comparatively better, which is a point in their favor — though I still dust them, because "better than most" isn't "complete."

A quick honesty note on the numbers you'll see online: silkworms are often advertised as "60% protein." That figure is on a dry-matter basis. Because a live silkworm is mostly water, the as-fed protein is far lower, and the fat is genuinely low. The practical takeaways hold up — lean, hydrating, soft, easy to digest — without needing to oversell a single percentage.

The role silkworms play — and don't

Here's the correction that matters most: crested geckos are omnivores, not insectivores, and silkworms are a supplement, not a staple. Unlike a leopard gecko, a crested gecko's nutrition should be built on a complete commercial crested gecko diet (CGD) — the mulberry-or-fruit-based powder you mix with water that's formulated to be nutritionally complete on its own. Silkworms (and other insects) add protein, enrichment, and a hunting outlet on top of that foundation.

Used that way, a sensible rhythm is offering silkworms a few times a week at most, alongside CGD as the everyday staple and small amounts of pureed soft fruit as an occasional treat. If you're tempted to run a crestie on insects and fruit alone, don't — it's much harder to balance and is a common cause of calcium problems. (For the full picture, see my crested gecko care guide.)

Silkworms vs. the other feeders cresties get offered

It helps to see where silkworms sit relative to the usual options:

The pattern that matters: silkworms beat the fatty feeders (mealworms, waxworms) decisively on body condition, and they edge crickets on softness and moisture. They aren't higher in protein than a good roach, but for a species that doesn't lean on insects for the bulk of its diet, "lean, soft, hydrating, and eagerly eaten" is exactly the profile you want in a supplement. Because metabolic bone disease is the main nutritional risk for a crested gecko, that comparatively decent calcium plus a light dusting is the part that earns silkworms their spot. The Merck Veterinary Manual's reptile nutrition section is a good non-commercial reference on calcium, D3, and preventing MBD.

Sizing silkworms to your gecko

Silkworms are sold by size, from tiny to large, and matching the worm to the gecko matters:

• ◆Hatchlings and juveniles: small silkworms. Their soft body and moisture make them an excellent feeder for young cresties, but the worm must be no wider than the space between the gecko's eyes.
• ◆Adults: medium silkworms work for most adult crested geckos. Large silkworms can be too big for a crestie's relatively small mouth, so err smaller.

A feeder that's too large is a choking and impaction risk and often just gets refused, so when in doubt, size down.

Why silkworms are a little fussier to keep

It's worth understanding what you're buying. Silkworms are the larvae of the domestic silk moth (Bombyx mori), an insect so thoroughly domesticated over thousands of years of silk farming that it no longer exists in the wild and depends entirely on people. That history is why they're a bit more delicate than feeders like roaches: they're bred for a narrow diet (mulberry) and comfortable conditions, not for surviving neglect. The upside of all that domestication is a clean, slow-moving, soft-bodied feeder with no bite, no odor, and no escape risk — about as low-stress an insect as you can hand to a nervous new keeper. Just plan to use them while fresh rather than stockpiling them the way you might with hardier feeders.

How to introduce silkworms

If your gecko has never seen a silkworm, ease it in:

1. ◆Start as a treat. Offer a silkworm or two alongside the regular diet rather than as a full meal, so it's a low-stakes introduction.
2. ◆Mix it into variety. Rotate silkworms with other appropriate feeders so your gecko comes to expect a varied menu rather than fixating on one item.
3. ◆Watch the response. If your gecko eagerly takes them, you can offer them more regularly within the few-times-a-week guideline. If it ignores them, the slow wriggle on a branch or a gentle tong-wiggle often triggers the strike.

Size every worm to the gecko: no wider than the space between its eyes, and small silkworms for hatchlings and juveniles.

Serving and supplementation

• ◆Dust with calcium. Give silkworms a light dusting of plain calcium before offering them. They're better than most feeders on calcium, but dusting is cheap insurance against metabolic bone disease — especially if you don't run UVB.
• ◆Offer in a dish or by tongs. A shallow, smooth dish keeps the worms from wandering and teaches your gecko where food appears; tongs make for interactive feeding and let you confirm each worm is dusted.
• ◆Don't overdo it. Silkworms are healthy, but more isn't better. They supplement the CGD; they don't replace it.

Keeping silkworms alive at home

Silkworms are a little fussier to hold than roaches, so a couple of rules keep them going:

• ◆Feed them mulberry. Fresh mulberry leaves or a prepared mulberry-based silkworm chow is their only food. No mulberry, no thriving silkworms.
• ◆Keep them dry and ventilated. A ventilated container at room temperature is ideal. Condensation and excess moisture kill silkworms quickly, so wipe down any damp and don't let them sit in wet bedding.
• ◆Do not refrigerate. This is the big difference from feeders like BSFL — cold harms silkworms. Keep them at room temperature, not in the fridge.

Because they don't store for weeks the way some feeders do, I treat silkworms as a "buy as needed" variety feeder rather than something I stockpile.

Common mistakes to avoid

A few errors turn a great feeder into a frustrating one:

• ◆Treating silkworms as the staple. They're a supplement. A crested gecko's foundation is a complete CGD; silkworms add variety and protein on top. Run a crestie on insects and fruit alone and you invite calcium problems.
• ◆Refrigerating them. This is the big one. Silkworms are not roaches or BSFL — cold harms them. Keep them at room temperature.
• ◆Letting the container get damp. Condensation and excess moisture kill silkworms fast. Keep their container ventilated and dry, and wipe away any moisture.
• ◆Skipping the mulberry. Silkworms only eat mulberry leaves or mulberry-based chow. Without it they decline quickly, so plan to use them while fresh rather than holding them for weeks.
• ◆Offering worms that are too big. A silkworm wider than the gap between the gecko's eyes is a choking risk and often gets refused. Size down when unsure.

Get those right and silkworms are one of the easiest wins in the whole rotation — a feeder your gecko is genuinely excited to see.

Bottom line

Silkworms are a soft, lean, hydrating, easy-to-digest feeder that crested geckos love — an excellent way to add protein, enrichment, and a little hunting fun to the diet. Use them as a supplement a few times a week, keep a complete crested gecko diet as the foundation, dust lightly with calcium, size the worm to the gecko, and keep them on mulberry at room temperature. Do that and silkworms become one of the most rewarding extras in your crestie's rotation. You can pick up live silkworms here.

New to crested geckos? Start with my crested gecko care guide. Curious how silkworms compare to other feeders? Browse the full exotic animal care library.