Feeding Silkworms to Monitor Lizards: A Practical Guide
- Role
- Rotation supplement
- Protein
- ~11%
- Fat
- ~2%
- Moisture
- ~80%
- Chitin
- very low
- Ca:P
- ~1:2
- Calcium-rich
- No (dust it)
- Best for
- Soft-bodied protein for picky or recovering animals
I've fed silkworms to insectivorous lizards for years, and they've become one of my go-to soft-bodied feeders for monitors in particular. Monitor lizards are intelligent, active, and prone to obesity in captivity, so a lean, highly digestible, protein-dense feeder earns its place fast. Silkworms (Bombyx mori) fit that brief better than almost anything else in the feeder lineup.
This guide covers why silkworms work for monitors, how to size and schedule them, the live-versus-home-raised question, and the storage and supplementation details that separate a good feeding from a wasted one.
Why Silkworms Suit Monitor Lizards
Silkworms bring a genuinely useful nutritional profile to a monitor's diet.
- High protein on a dry-weight basis, which supports the muscle development active monitors need.
- Very low fat — silkworms are one of the leanest common feeders. For a group of animals that pile on weight easily in captivity, that's a real advantage.
- High moisture content (silkworms are soft and water-rich), which contributes to hydration.
- Soft, chitin-free bodies that digest easily and carry low impaction risk, making them safe down to juvenile monitors.
A note on the nutrition claims you'll see repeated online: silkworms are often described as "high calcium" with a favorable calcium-to-phosphorus ratio. The honest version is that silkworms are better balanced than most feeders but still lean phosphorus-heavy, so you should still dust with calcium for growing animals. They are not a calcium source the way black soldier fly larvae (BSFL) are — BSFL are the one common feeder that's genuinely calcium-positive. Treat silkworms as the lean, clean protein in your rotation, and let dusting and other feeders cover calcium.
Sizing and Feeding Strategy
Getting silkworms into a monitor's diet is mostly about sizing and pacing.
Match the worm to the lizard
The standard rule applies: a feeder should be no wider than the space between the monitor's eyes (and never longer than the width of the head). Silkworms are sold in sizes from tiny hatchlings to large 3-inch worms, so you can match almost any monitor. Oversized prey is the main avoidable risk with any feeder.
Introduce gradually
Monitors can be neophobic. If yours has never seen a silkworm:
- Start small. Offer a few silkworms alongside a familiar feeder so they're not the whole meal.
- Use movement. Live silkworms wriggling in a shallow dish or offered with feeding tongs trigger the feeding response better than still ones.
- Be patient. A picky monitor may ignore them the first time or two, then take them readily once they're recognized as food.
Build a rotation, don't go all-in
Silkworms should be part of a diversified diet, not the entire thing. Rotate them with other feeder insects, and for larger monitors include appropriate whole-prey items. A reasonable shape for an insect-heavy monitor is silkworms as one of several rotating feeders a few times a week, scaled to the animal's age and condition. Growing juveniles eat more frequently than adults; adults should be fed to maintain a lean body condition, not stuffed.
Live, Commercial, or Home-Raised?
You have three practical options, and they trade off convenience against cost and control.
| Option | Pros | Cons |
|---|---|---|
| Live, commercially shipped | Fresh, enticing movement, sized to order, no setup | Costs more per worm; need to use within their window |
| Home-raised | Cheapest long-term; full control of diet and freshness | Requires mulberry chow, space, and patience |
| Frozen / dried | Long shelf life, zero maintenance | Less nutritious, less enticing, no movement |
For most monitor keepers, live shipped silkworms are the right default — they arrive fresh, you pick the size, and there's no colony to maintain. If you feed enough volume to justify it, raising your own pays off and gives you total control over freshness and feeding (silkworms eat only mulberry leaves or commercial mulberry chow). Frozen or dried are a fine backup but shouldn't be the staple, since monitors respond far better to live, moving prey.
Storage, Handling, and Supplementation
Silkworms are a little more delicate than roaches, so handling matters.
- Storage temperature: keep them around 70-80°F in their rearing container. Too cold stalls them; too hot and humid invites die-off.
- Keep them clean and dry-ish: check the container every few days, remove droppings (frass) and any dead worms, and keep their chow fresh. Damp, dirty containers are what kill silkworms before they get eaten.
- Hydration: silkworms are already moisture-rich, but your monitor still needs constant access to fresh drinking water.
- Supplementation: lightly dust silkworms with a calcium powder before feeding, especially for juveniles and gravid females. This is the simple insurance that keeps the calcium-to-phosphorus ratio on the right side of the line.
- Watch the animal, not just the worm: after introducing silkworms, keep an eye on appetite, stool, and body condition so you can fine-tune how often you offer them.
You can source correctly sized live silkworms with a live-arrival guarantee — shop silkworms at All Angles Creatures — which saves the hassle of maintaining a colony for occasional feedings. For broader guidance on insectivore nutrition and supplementation, the Merck Veterinary Manual's reptile nutrition section is a solid, non-commercial reference (MSD/Merck Veterinary Manual: Nutrition in Reptiles).
Silkworms won't replace a monitor's whole diet, but as the lean, soft, easily digested part of the rotation, they're one of the most useful feeders you can keep on hand.
For the full nutritional case on this feeder, see 5 surprising benefits of silkworms, and to see where silkworms rank against every other feeder, read the best feeder insects ranking.