Best Feeder Insects for Leopard Geckos, Ranked

I've fed leopard geckos for years, and the single biggest lever on their long-term health isn't the lamp or the substrate. It's what's wriggling in the bowl. Leos are obligate insectivores, so the feeder you pick is the diet. Most keepers default to mealworms because they sit in the fridge, and that convenience quietly causes most of the obesity and bone disease I see. Here's how I actually rank the common feeders, and the rotation I run.

The ranking at a glance

Ratings below weigh nutrition, bite/injury risk, size-fit for an adult leo, and how easy the feeder is to keep alive.

#1: Discoid roach nymphs

Small discoid roaches (Blaberus discoidalis) at 3/8 to 1/2 inch are, to me, the ideal staple. They run around 20% protein with moderate fat, they are highly gut-loadable, and they do not bite a sleeping gecko. Critically for a glass tank, discoids cannot climb smooth vertical surfaces, so an escapee stays in the bowl or on the floor rather than scaling the walls. They live for months at room temperature with almost no fuss.

One honest correction to what you'll read elsewhere: discoids are not calcium-rich. Like nearly every feeder insect, they carry far more phosphorus than calcium, so you still dust them with plain calcium powder. The advantage is the protein-to-fat profile and the safety, not a magic mineral ratio.

#2: Black soldier fly larvae (BSFL)

BSFL are the one genuine exception to the "all feeders are phosphorus-heavy" rule. They are naturally calcium-rich (commonly cited around 9,000+ mg/kg with a positive calcium-to-phosphorus ratio), which makes them the rare feeder you don't have to dust. For leos raised on mealworm-heavy diets that drift toward calcium deficiency, BSFL are a quiet fix. Offer 5 to 10 in a smooth-sided dish once or twice a week. They are a calcium supplement, not a protein staple.

#3: Silkworms

Small silkworms are very lean (roughly 1% fat) with a soft body and no hard chitin, so they digest easily. They're my go-to for an overweight leo on a slimming plan, or for a gecko recovering from impaction or illness. Downside: they're perishable and need mulberry-based chow, so they're a variety feeder rather than a stockpile staple.

#4: Hornworms

Small hornworms are about 85% moisture, so they double as hydration and enrichment. The bright color and movement trigger feeding in picky or post-shed geckos. The catch is size: hornworms grow fast and can balloon past a safe size within days. Buy small, feed small, and never offer one wider than the space between the gecko's eyes.

#5: Crickets

Crickets work, but they're a clear step down from roaches. They bite, and leos have genuinely lost toes to crickets left in the tank overnight. They also smell, chirp, jump, and escape. Their calcium-to-phosphorus ratio is poor, so dusting is mandatory. If roaches aren't available, crickets are a serviceable fallback, gut-loaded and dusted.

#6: Mealworms, the default that shouldn't be

Mealworms earned their popularity through fridge storage, not nutrition. At roughly 13% fat with a poor calcium ratio, a mealworm-only diet is the fast lane to obesity and metabolic bone disease, the two problems I most often see in surrendered leos. They're fine as an occasional backup, once a week at most, but they should never be the base.

#7 and #8: Superworms and waxworms

Superworms are large with strong mandibles and high fat. They're too big and too rich for most adult leos as a regular item; reserve them for occasional treats or for putting weight back on a thin animal. Waxworms are roughly 25% fat and effectively candy. Geckos hooked on waxworms routinely refuse everything else. Use them only to coax a sick or underweight gecko to eat, then wean off immediately.

My weekly rotation

Three feeding days covers an adult leo's protein and calcium without a single mealworm:

• ◆Monday: 5 small discoid roach nymphs, dusted with plain calcium
• ◆Thursday: 8 BSFL plus 3 small silkworms (no dusting needed on the BSFL)
• ◆Saturday: 5 small discoid roach nymphs, dusted with calcium plus D3 every other week

Juveniles eat the same feeders daily instead of three times a week. Keep clean water available, run a multivitamin roughly every two weeks, and watch the tail: a plump tail and a non-bulging belly is the body condition you're aiming for.

You can browse live feeder insects at All Angles Creatures to build this rotation. For the underlying numbers, university extension programs publish solid feeder-insect nutrition data; the University of Florida IFAS extension is a reliable starting point.

For deeper dives, see discoid roaches vs BSFL and how to keep discoid roaches alive.