How Many Silkworms to Feed Your Reptile, by Species

Silkworms are one of my favorite feeders to recommend, but they're constantly misused. People hear "soft, low-fat, nutritious" and try to run a whole reptile on them. Silkworms are a premium supplement, not a protein staple — feed them alongside a staple like discoid roaches, not instead of one. Below are the per-feeding amounts I actually use, organized by species, plus the principles that keep them useful rather than just expensive.

Quantities by species

Sizes matter here: a "small" silkworm is a few millimeters; a "large" is roughly an inch. Always keep the prey no wider than the space between your animal's eyes.

These are starting points for healthy animals. Scale down for sedentary or overweight individuals, and up slightly for fast-growing juveniles — but for juveniles the answer is usually more frequent feedings, not bigger prey.

Why silkworms earn a spot

What makes silkworms worth the premium isn't a single headline number — it's the overall profile. They're soft-bodied (easy to digest, low impaction risk), low in fat, well-hydrated, and high in moisture, and they contain a natural compound called serrapeptase that some keepers find sits well with sensitive animals. Most usefully, they're palatable enough to tempt an animal that's gone off its food without being so addictive that they cause the food-refusal problems waxworms are notorious for.

That last point is why I keep silkworms on hand even when no one's being picky: when a leo or chameleon stops eating after a move, a shed, or a vet visit, silkworms are often the feeder that gets them started again.

The principles that keep silkworms working

They're a supplement, not a staple

Build the week around a protein-dense staple — discoid roaches are mine — and use silkworms to add variety, moisture, and a gentler option. Running a reptile entirely on silkworms underfeeds protein over time.

Dust them with calcium

Here's the correction I make most often: silkworms are not a complete calcium source. Like nearly every feeder insect, they're phosphorus-heavy, so dust them with a calcium supplement (with D3 periodically, per your UVB setup) before offering. The one feeder that genuinely doesn't need dusting is BSFL, whose calcium already exceeds its phosphorus — which is exactly why I pair the two. You can browse sizes in the silkworms collection.

Size to the animal

No prey item should be wider than the gap between your animal's eyes. Silkworms come in a wide size range precisely so you can match hatchlings through adults; order the size band that fits, not the biggest available.

Use them as the picky-eater fix

If your reptile is refusing food, offer silkworms first. Their palatability and soft body make them the feeder most likely to break a hunger strike.

A sample rotation

For a typical insectivore like a leopard gecko, a balanced week looks like:

• ◆Staple, every 2-3 days: discoid roach nymphs, calcium-dusted
• ◆2-3x/week: silkworms, calcium-dusted, for low-fat variety
• ◆2-3x/week: BSFL for the calcium boost (no dusting needed)
• ◆Rare treat only: waxworms or hornworms

Omnivores like bearded dragons and blue tongue skinks get the same insect rotation plus their greens and vegetables.

For exact numbers on the calcium side of that rotation, see how many BSFL to feed your reptile by species. For a deeper look at silkworms specifically with leopard geckos, see how to feed silkworms to leopard geckos.

A note on accuracy

Feeder nutrition numbers vary by source, gut-load, and life stage, so treat any single figure as a ballpark. What doesn't vary is the principle: no feeder is a complete diet by itself, and calcium balance is the thing most likely to hurt your animal if you ignore it. The Merck Veterinary Manual's reptile nutrition overview is a good non-commercial reference if you want to go deeper.

See also how many silkworms to feed a leopard gecko and the exotic animals hub for the full library.