Feeder Insects Compared: How the Common Options Really Stack Up
Walk into the feeder section of any reptile shop and the choices multiply fast: crickets, mealworms, superworms, roaches, black soldier fly larvae, silkworms, hornworms, waxworms, butterworms, even locusts. They are genuinely not interchangeable. Each has a nutritional fingerprint and a job it does best, and the difference between a thriving animal and a struggling one is often just whether the keeper matched feeders to needs. This is the side-by-side comparison I wish every new keeper got handed on day one.
The four things that actually differ
When you compare feeders, four properties drive almost every decision:
- Protein — for growth, muscle, and repair. Staples need a solid amount; treats can be low.
- Fat — energy, but excess drives obesity and fatty-liver disease. Low fat is good for staples; high fat is for fattening, only occasionally.
- Moisture — hydration. High-moisture feeders help desert species and sick or shedding animals.
- Calcium and the calcium-to-phosphorus (Ca:P) ratio — the make-or-break mineral for reptiles. The honest truth most marketing hides: nearly every feeder insect is phosphorus-heavy and low in calcium, so you dust with a calcium supplement. The one real exception is black soldier fly larvae.
A fifth, practical factor — the body and chitin — decides digestibility: soft, low-chitin feeders are gentle and low-impaction; hard-shelled ones are tougher on the gut.
The lineup
Crickets — the classic staple
The default feeder for decades. Crickets are moderate in protein (~18–20%), low-to-moderate in fat, moderately high in moisture, and come in every size from pinhead to adult, so they suit any animal. Their movement triggers strong feeding responses. Downsides: they're noisy, smelly if not cleaned, short-lived, and have a higher-chitin shell than roaches. Calcium is poor — gut-load and dust. A perfectly good staple, just higher-maintenance than roaches.
Discoid and dubia roaches — the workhorse staples
Roaches are what I steer most keepers toward for the bulk of the diet. High protein (~20%), moderate fat (~6–8%), soft and low-chitin (easy to digest, low impaction risk), nearly odorless, quiet, and — for discoids and dubia — unable to climb smooth walls or fly, which makes them easy to contain and breed. Discoids are legal in places like Florida where dubia are restricted; nutritionally the two are nearly identical. Like all feeders, they're phosphorus-heavy, so dust with calcium. If you build your diet on one feeder, make it a roach.
Mealworms — convenient, fatty, hard-shelled
The larvae of the darkling beetle: cheap, available everywhere, and storable (they tolerate the fridge). But they're higher in fat (~13–18%) with a tough, chitin-heavy shell that's harder to digest and riskier for impaction in small animals. Calcium is poor. Fine as an occasional treat, weak as a staple.
Superworms — the high-energy treat
Bigger, meatier cousins of mealworms. Moderate protein (~18%) but high fat (~15%) with a hard head capsule. Active and tempting, great for putting weight on a thin animal or as a high-value reward — but the fat makes them a treat, not a staple, and they bite, so crush the head for small or sick animals. Don't refrigerate them (cold kills superworms, unlike mealworms).
Black soldier fly larvae (BSFL) — the calcium champion
The standout exception on minerals. BSFL have a genuinely favorable Ca:P ratio (around 1.5:1) — meaning they actively support bone health and, in most cases, don't need calcium dusting. They're soft, low-chitin, easy to digest, low-maintenance, and odorless. Protein is moderate and they're smaller than roaches, so larger animals need more of them. For any reptile prone to metabolic bone disease, BSFL belong in the rotation.
Silkworms — soft, lean, and clean
The larvae of the silk moth, raised on mulberry. Soft-bodied, lean (low fat), and protein-rich on a dry-matter basis, with decent calcium and a clean profile (their pure mulberry diet leaves them odorless). Excellent for animals that struggle with tougher prey, and a favorite for sick or recovering reptiles. Downsides: pricier, shorter-lived, and need mulberry or mulberry chow to keep.
Hornworms — the hydration specialist
Soft green caterpillars that are roughly 85% water, very low fat, low protein (~9%), and carry more calcium than most insects. Unbeatable for hydration and for tempting picky or recovering eaters, and gentle on digestion. But the low protein means they're a treat, not a staple — and only ever feed commercially chow-raised hornworms, since wild ones can be toxic.
Waxworms and butterworms — fatty indulgences
Both are very high in fat and intensely palatable — the candy of the feeder world. Waxworms are the classic pick-eater tempter and fattening tool. Butterworms carry more calcium than waxworms, a small bonus, but are pricey and harder to source. Use both sparingly; overuse causes obesity and "treat addiction" where animals refuse leaner food.
Locusts and grasshoppers — lean and stimulating
Where available, locusts and grasshoppers are lean, high-protein, and visually stimulating thanks to their size and movement — great for larger reptiles and birds. They're seasonal and harder to source in much of North America, and wild-caught ones risk pesticide exposure, so source carefully.
The comparison table
Approximate as-fed figures — real values shift with diet, age, and source, but the relationships are what guide your choices:
| Feeder | Protein | Fat | Moisture | Body / digestibility | Calcium | Best role |
|---|---|---|---|---|---|---|
| Discoid / dubia roach | High (~20%) | Moderate (~6–8%) | ~60% | Soft, low chitin | Low — dust | Staple |
| Cricket | Moderate (~18–20%) | Low–moderate (~6%) | ~70% | Higher chitin | Low — dust | Staple / variety |
| Black soldier fly larvae | Moderate | Moderate | ~60% | Soft, easy | Good (~1.5:1) | Calcium / variety |
| Silkworm | Good (lean) | Low | ~80% | Very soft | Decent | Lean variety / sick animals |
| Mealworm | Moderate (~20%) | High (~13–18%) | ~62% | Hard shell | Low — dust | Occasional treat |
| Superworm | Moderate (~18%) | High (~15%) | ~60% | Hard head | Low — dust | Occasional treat |
| Hornworm | Low (~9%) | Very low (~3%) | ~85% | Very soft | Better than most | Hydration / treat |
| Waxworm | Low–moderate | Very high (~20%+) | ~60% | Very soft | Low | Fattening treat |
| Locust / grasshopper | High, lean | Low | high | Tougher chitin | Low — dust | Lean variety (seasonal) |
How to actually use this
The single best habit isn't picking the "right" feeder — it's building a rotation:
- Anchor on a staple. A discoid or dubia roach for most keepers (high protein, low fat, easy to digest, breeds at home). Crickets are a fine co-staple.
- Add black soldier fly larvae for calcium, especially for species prone to metabolic bone disease — they're the one feeder that fixes rather than worsens the mineral balance.
- Keep hornworms on hand for hydration and for picky or recovering animals.
- Use fatty feeders sparingly — superworms, waxworms, butterworms — as occasional treats or to fatten a thin animal.
- Gut-load everything for 24–48 hours before feeding, and dust with calcium for every feeder except (usually) BSFL.
- Match size to the animal — no feeder longer than the space between the eyes.
Variety isn't just enrichment; it's insurance. No single insect covers every nutritional base, but a thoughtful rotation does — and it keeps a supply gap from leaving you stuck. When you want to stock that rotation from healthy, well-kept stock, All Angles Creatures carries a full range of live feeder insects.
For the mineral-balance and metabolic-bone-disease science underneath all of this, the Merck Veterinary Manual's reptile nutrition section is a reliable, non-commercial reference; for the bigger picture on insects as a sustainable protein source, see the FAO's work on edible insects.
Want to go deeper on individual feeders? See my discoid roach breeder's playbook, my complete hornworm guide, and my guide to raising superworms — or browse the full feeder insect care library.