How to Choose the Right Feeder Insect for Your Reptile
After years of keeping geckos and other insectivores, the question I get most isn't "how do I care for my animal" — it's "which bug do I actually buy?" The feeder aisle is overwhelming because every option is sold as essential. It isn't. Each feeder has one or two real strengths, and once you match those strengths to what your animal needs, the choice gets simple.
Start with the question: what's the job?
Don't pick a bug. Pick a job, then pick the bug that does it best. Here's how I sort them.
Daily protein staple → discoid roaches
About 20% protein, 7% fat, fully gut-loadable, and they live for months in a bin. They're silent, odorless, and — contrary to a stubborn myth — discoid roaches (Blaberus discoidalis) cannot climb smooth vertical surfaces, so a bin with slick walls holds them with no lid drama. This is the foundation of almost every rotation. Dust with calcium plus D3.
Low-fat supplement (obesity prevention) → silkworms
Around 1% fat, the leanest feeder there is. Perfect for sedentary adults, overweight leopard geckos, and any animal prone to packing on weight. Two to three times a week.
Calcium without dusting → black soldier fly larvae (BSFL)
The only feeder with a natural calcium surplus, so you can skip the powder. One to three times a week is excellent insurance against metabolic bone disease.
Hydration and appetite → hornworms
Roughly 85% moisture. The bright color and movement trigger explosive feeding responses, which makes them my go-to for a dehydrated or picky animal. One to three times a week.
Convenient fridge backup (adults only) → mealworms
Unbeatable storage, but ~13% fat and a poor mineral ratio, and the tough chitin is risky for juveniles. An occasional supplement, never a staple.
High-energy treat (adults only, rare) → superworms
About 20% protein but ~18% fat, with strong mandibles that can bite. Once a week at most, adults only, and never refrigerated.
Appetite rescue (last resort) → waxworms
Roughly 25% fat and genuinely addictive. I reserve these for sick animals refusing everything else.
Match it to your animal
The job-based view gets you most of the way; here's how it lands per species.
| Animal | Daily staple | Key supplements |
|---|---|---|
| Leopard gecko | Discoid roach nymphs | Silkworms, BSFL, occasional mealworms |
| Crested gecko | CGD (powdered diet) | Small silkworms, BSFL, small roach nymphs |
| African fat-tailed gecko | Discoid roach nymphs | Silkworms, BSFL, hornworms |
| Bearded dragon | Discoid roaches + greens | Silkworms, BSFL, hornworms |
| Chameleon | Discoid roach nymphs | Silkworms (top cham feeder), hornworms, BSFL |
| Ball python | Frozen/thawed rodents | Not insectivorous — isopods/springtails for bioactive |
| Dart frog | Fruit flies | Springtails, tiny BSFL |
Two things worth flagging. Crested geckos are primarily fed a complete powdered diet, so insects are enrichment rather than the main course. And ball pythons aren't insectivores at all — they eat rodents — though their bioactive enclosures still benefit from a cleanup crew.
My honest default
If you're standing there frozen, start with a quality protein staple and build out from there. The single safest first purchase for nearly any insectivorous gecko is a tub of live feeder insects built around gut-loaded discoid roaches — they work for virtually every species, and you can layer in silkworms, BSFL, and hornworms once you see how your animal eats.
The mistake I see most is buying one feeder and feeding it forever. Variety isn't a luxury here; it's how you avoid the slow deficiencies that show up months later as a fat tail, a soft jaw, or a gecko that's stopped eating.
Next, dial in quantities and sizing with the eyes-width sizing rule and my complete leopard gecko diet guide.
Sources: Finke, M.D. (2013). "Complete nutrient content of four species of feeder insects." Zoo Biology 32:27-36. doi:10.1002/zoo.21012 · MSD Veterinary Manual — Nutrition in Reptiles