Best High-Calcium Feeder Insects for Reptiles (Ranked)

The Best High-Calcium Feeder Insects, Ranked

Calcium is the most important mineral for captive reptile health. Without it, reptiles develop metabolic bone disease (MBD) — soft bones, tremors, paralysis, and death. Choosing high-calcium feeder insects is one of the most effective ways to prevent MBD naturally.

This ranking evaluates feeder insects specifically by calcium content and calcium-to-phosphorus ratio — the two metrics that matter most for bone health.

The Rankings

#1: Black Soldier Fly Larvae (BSFL)

Calcium: ~9,340 mg/kg | Ca:P Ratio: 6.92:1

BSFL dominate this category so completely that no other feeder is close. They contain 50 times more calcium than mealworms and are the only feeder that does not require calcium dusting. The 6.92:1 Ca:P ratio means your reptile absorbs a massive calcium surplus with every feeding.

Best for: Calcium supplementation 1-3x/week for all insectivorous reptiles. Also excellent for backyard chickens.

#2: Hornworms

Calcium: ~460 mg/kg | Ca:P Ratio: 3.07:1

Hornworms are the second-best calcium feeder, with a Ca:P ratio above 3:1. They also provide exceptional hydration at 85% moisture. While they have far less total calcium than BSFL, their positive Ca:P ratio means they still contribute to calcium balance rather than depleting it.

Best for: Hydration + calcium supplement 1-2x/week.

#3: Silkworms

Calcium: ~340 mg/kg | Ca:P Ratio: 0.77:1

Silkworms have moderate calcium with a near-neutral Ca:P ratio. Not positive like BSFL or hornworms, but dramatically better than crickets or mealworms. Combined with their ultra-low fat (1%) and the serrapeptase enzyme, silkworms are a premium supplement even if calcium is not their strongest suit.

Best for: Low-fat premium supplement 2-3x/week. Dust with calcium.

#4: Discoid Roaches

Calcium: ~200 mg/kg | Ca:P Ratio: 0.77:1

Discoid roaches provide moderate calcium with the same 0.77:1 ratio as silkworms. Their real strength is protein (20%) — they are the ideal daily staple, not a calcium specialist. Dust with calcium + D3 at every feeding to compensate for the phosphorus-heavy profile.

Best for: Daily protein staple. Always dust with calcium.

#5: Crickets

Calcium: ~140 mg/kg | Ca:P Ratio: 0.13:1

Crickets have poor calcium content and one of the worst Ca:P ratios of any feeder. Heavy calcium dusting is essential when feeding crickets — and even then, the phosphorus load works against absorption.

#6: Superworms

Calcium: ~100 mg/kg | Ca:P Ratio: 0.16:1

Similar to crickets — low calcium, phosphorus-heavy. Dust heavily if used.

#7: Mealworms

Calcium: ~30 mg/kg | Ca:P Ratio: 0.04:1

The worst calcium profile of any common feeder. Mealworms contain 311 times less calcium than BSFL and have a Ca:P ratio so inverted that calcium absorption is severely compromised even with heavy dusting. This is why mealworm-heavy diets are strongly associated with MBD.

The Complete Calcium Strategy

This four-pillar approach — UVB, dusting, BSFL supplementation, and gut loading — creates the most comprehensive MBD prevention strategy available.

Browse our high-calcium feeder collection and give your reptile the bone-building nutrition it needs.

— Matt, Founder, All Angles Creatures