Waxworms 101: How to Buy, Store, and Feed the Reptile World's Favorite Treat

Waxworms are the candy bar of the feeder world, and I mean that as both a compliment and a warning. Almost every insectivore on earth goes nuts for them, they're dead simple to keep, and they're the single best tool I have for fattening up a thin animal or coaxing a sick one to eat. They're also pure indulgence — too fatty to feed every day — and most keepers either underuse them or badly overuse them. This is everything you actually need to get started: what they are, how to store them so they don't melt into a moldy mess, how to feed them, and how to keep them in their lane.

What a waxworm actually is

A waxworm is the larval (caterpillar) stage of the greater wax moth, Galleria mellonella. In nature, the moth lays eggs inside or near honeybee hives, and the larvae burrow through the comb eating beeswax, honey, pollen, and hive debris — which is exactly why beekeepers despise them and why they're so fat and palatable. That waxy, honey-rich diet loads them with energy.

Fully grown, a waxworm is a soft, plump, cream-colored grub with a small brown head, ridged segments, and a length of roughly 0.75 to 1 inch. They're slow, they don't fly, they don't jump, and adults can't really scale smooth surfaces — which makes them about the most beginner-friendly feeder you can hand someone.

The life cycle, briefly

Like all moths they go through four stages — egg, larva (the waxworm), pupa (a silk cocoon), and adult moth. The whole point of how you store them is to freeze that life cycle at the larva stage for as long as possible. Warm them up and they cocoon and turn into drab gray-brown moths within days to a couple of weeks; keep them cool and they hold as feeders for a month or more.

Why keepers love them

• ◆Irresistible palatability. Their softness and slight sweetness make them the go-to for picky eaters, animals on a feeding strike, and anything you need to tempt.
• ◆Energy density. That high fat content is genuinely useful for underweight animals, animals recovering from illness or injury, and breeding females that need to rebuild condition.
• ◆Stupid-easy handling. No jumping, no flying, no chirping, no escaping up the walls. You scoop them out with your fingers or tweezers and they sit there.
• ◆Long shelf life. Stored cool, they last for weeks with essentially no care, so you're not running to a store mid-week.

The catch: nutrition

Here's the honest nutritional picture and why I never treat them as a staple. Waxworms are very high in fat (commonly in the 20-25% range) with only moderate protein (around 15%) and a poor, phosphorus-heavy calcium ratio. They're also high in moisture.

Feed waxworms as a main diet and you get the predictable results: obesity, fatty liver disease, and — maddeningly — animals that learn to hold out for waxworms and refuse their healthier feeders, like a kid who skips dinner waiting for dessert. The fix is simple: treat them as a treat. A few a week as enrichment, or a short fattening course for an animal that needs it, and then back to staples.

How to source good waxworms

Quality varies a lot, so inspect before you buy or before you feed:

• ◆Plumpness. Healthy waxworms are firm and fat, not shriveled or shrunken.
• ◆Color. Pale cream to light beige is what you want. Dark spots, blackening, or graying signals disease or death.
• ◆Behavior and smell. They're not athletic, but a healthy one twitches when nudged. There should be no foul odor — a sour or rotten smell means the batch is going off.

Buy from a supplier that ships in insulated, ventilated packaging, because waxworms are genuinely sensitive to heat and crushing in transit. When I'm restocking my treat supply I get waxworms from All Angles Creatures, which arrive plump and properly bedded.

Storing waxworms so they actually last

This is where most people lose half a cup of waxworms to mold. The rules are short:

• ◆Keep them cool: about 55-60°F (13-16°C). This slows their metabolism and stops them pupating. A wine fridge is ideal; otherwise the door or a warmer drawer of a regular refrigerator works — never the coldest part, which can chill-kill them.
• ◆Use a breathable container. Small ventilation holes or a mesh lid. Never seal them airtight — trapped humidity is what causes mold and suffocation.
• ◆Leave them in their bedding. They ship in a bran/sawdust substrate that doubles as bedding and a little food. Keep it dry. If it gets damp or moldy, replace it with fresh dry bran or oats immediately.
• ◆Keep it dry, full stop. Waxworms hate humidity. No misting, no damp sponge, no condensation. If you see beads of water inside the container, you're cooking up mold.
• ◆Inspect and cull. Once a week, tip them out gently, pull any dead, blackened, or shriveled worms, and check for cocoons. One rotting worm contaminates the rest fast.

Done right, a cup keeps for several weeks. The classic mistakes are storing them too cold (they die), too warm (they all turn to moths), or too wet (mold).

Feeding them off

• ◆Warm them to room temperature for a few minutes before offering — a cold, sluggish worm is less enticing, and you don't want to feed a fridge-cold insect.
• ◆Dust lightly with calcium right before feeding to partly offset that poor mineral ratio. Real gut-loading is limited because they barely eat in storage, so dusting plus restraint is your main tool.
• ◆Portion small. This is the whole game. For most reptiles, a handful per week as a treat, not a daily ration. For a thin animal, a slightly heavier short course, then taper off.
• ◆Match the size and the mouth. They're soft and low-impaction-risk, which makes them safe for juveniles and sensitive eaters, but still size sensibly.

They suit a huge range of animals as a treat: bearded dragons, leopard and crested geckos, chameleons, turtles, frogs and toads, insectivorous birds, and many fish. Anglers also swear by them as bait — they're a favorite for trout and panfish in freshwater and ice fishing — but that's a different hobby.

Can you breed your own?

You can, and it's straightforward — though I'll be honest that for a treat feeder, most keepers don't bother. If you want a continuous supply:

• ◆Set up a breeding container — ventilated plastic or glass with small holes, a secure lid, and a substrate of bran or oatmeal mixed with a little honey (and glycerin if you have it). Add crumpled wax paper or cardboard as egg-laying surfaces.
• ◆Warm it up. Breeding runs best at 75-85°F with moderate humidity — the opposite of storage temperature. Warmth is what pushes larvae to pupate, turn into moths, and reproduce.
• ◆Let the cycle run. Mature worms pupate into cocoons, emerge as nocturnal gray-brown moths, mate, and lay tiny eggs on the paper or cardboard within days. Eggs hatch into new larvae in about one to two weeks.
• ◆Harvest and sustain. Pull larvae at feeding size while leaving some moths to keep laying. Keep it clean — mold from excess moisture is the main thing that crashes a colony.

The reason I usually skip it: a warm breeding bin smells faintly of fermenting honey, the moths are a minor escape nuisance, and the payoff is a feeder you only use occasionally anyway. If I'm going to run a colony, I'd rather it be roaches. But if you go through a lot of waxworms — say, for fish or a flock of insectivorous birds — breeding pays off.

A note on the science

Waxworms have a second life in the lab that's worth knowing about, because it's genuinely interesting and it comes up. Galleria mellonella can partially break down polyethylene plastic, which has made them a research subject in biodegradation studies. They're also widely used as a model organism for studying infection and testing antibiotics, since their immune system is simple and they're cheap to rear. None of that changes how you feed them — but it's a reminder there's more to this grub than dragon candy.

Where waxworms fit

Think of waxworms as the reward, never the meal. I build a diet around soft, nutritious staples and use waxworms to break a hunger strike, fatten a recovering animal, or just give a healthy one a bit of enrichment. If you want the actual workhorse feeders to build around, see my feeder debate guide and the silkworm guide — silkworms are the soft, high-value staple that waxworms only pretend to be. And if you've only ever bought waxworms off a big-box shelf, read whether those are worth it before your next trip.

The short version

Waxworms are the larvae of the greater wax moth — soft, fatty, irresistible, and a treat, not a staple. Store them cool (55-60°F), dry, and breathable, cull the dead ones weekly, dust with calcium and feed sparingly, and lean on them when you need to fatten up or tempt an animal. Respect the fat content and they're one of the most useful tools in your feeder kit.