Raising Black Soldier Fly Larvae at Home: A Keeper's Complete Guide

I've raised black soldier fly larvae alongside my feeder colonies for years, and they're still the most useful insect a keeper or small homesteader can produce at home. They eat food waste at a pace that's honestly hard to believe, turn it into protein-dense feeders, and — unlike houseflies — the adults don't bite, don't land on your food, and don't spread disease. A single home bin can process hundreds of pounds of kitchen scraps a year while feeding your reptiles, chickens, and fish. The setup is simpler than most people expect, and the larvae do most of the work themselves.

What you'll need

A basic small-scale BSFL bin doesn't take much:

• ◆A plastic bin, 15-20 gallons, with a lid
• ◆A drainage hole or an inclined ramp for self-harvesting
• ◆Bedding: coconut coir, shredded cardboard, or wood shavings
• ◆Starter larvae (50-100 to seed a colony)
• ◆Food scraps to feed them
• ◆Outdoor space that's semi-shaded and protected from direct rain

If you build the bin yourself, the whole setup usually runs under $50. Pre-built BSFL composters exist and run $150-300 with self-harvesting designed in, but you don't need one to get going — a drilled storage tote works fine.

How the BSFL lifecycle works

The full lifecycle runs about 38-45 days from egg to adult fly. Knowing the stages is what makes harvesting effortless:

• ◆Egg (3-4 days): females lay 500-900 eggs in cracks and crevices near food, not in the food itself.
• ◆Larval (14-22 days): the eating stage. Larvae move through five instars and feed constantly. This is the body of the colony.
• ◆Pre-pupal (5-7 days): larvae stop eating, darken to brown-black, and crawl AWAY from the food looking for a dry place to pupate. This migration is the whole trick behind self-harvesting.
• ◆Pupal (10-14 days): motionless brown pupae, tucked into dry bedding.
• ◆Adult fly (5-8 days): flies emerge, mate, lay eggs, and die. Adults don't eat at all.

For feeders you harvest pre-pupae as they self-migrate out. If you want them bigger, the larvae stay put in the food until they're full-grown.

The self-harvesting setup

The best feature of a BSFL bin is that it harvests itself. Pre-pupae instinctively climb up and out of the food to find a dry pupation site, so if you give them a ramp leading to a bucket, they collect themselves with zero labor from you.

To build it:

• ◆Cut or drill a hole in the upper sidewall of the bin
• ◆Attach a length of PVC or angled plastic tube at about a 45° angle, running down into a sealed collection bucket
• ◆Pre-pupae crawl up the ramp, drop into the bucket, and you scoop them out daily

Commercial composters have this built in, but a DIY ramp works just as well with basic plastic-cutting.

What to feed your BSFL

BSFL eat almost any organic material, but the quality of what goes in shapes the colony:

• ◆Excellent: fruit and vegetable scraps, coffee grounds, bread, grains, pasta, manure (chicken/cow/horse), spent brewing grain
• ◆Good: meat scraps, eggshells, small amounts of dairy
• ◆Avoid: pesticide-treated produce, bulk citrus peels (too acidic), large amounts of onion or garlic, oily cooked foods
• ◆Avoid entirely: anything moldy or deeply rotten — fresh waste is great, but rotten waste goes anaerobic and harms the larvae

Aim for about 1 lb of food per 1,000 larvae per day. A 5,000-larva bin handles around 5 lb of waste daily, which is a real dent in a household's scraps.

Temperature and conditions

BSFL thrive at 80-95°F (27-35°C). Below 70°F they slow dramatically; below 60°F they stop developing. In hot climates like Florida, Texas, or Arizona, an outdoor bin in full summer sun cooks them, so keep it shaded. In cold climates BSFL only run seasonally outdoors — some keepers run year-round bins in a heated garage or basement.

Humidity wants to sit around 60-70%. Too dry and the larvae dehydrate; too wet and the bin turns anaerobic and starts to smell. Toss in dry bedding — cardboard or wood shavings — anytime the bin gets soggy.

Starting your colony

There are two ways in:

1. ◆Buy starter larvae. Fifty to a hundred larvae will seed a colony. Drop them in with food and let it run — adults emerge, mate, and lay eggs to grow the population.
2. ◆Wild-attract. In BSFL-native climates (most of the southern US and other subtropical regions), set out a bait bin of attractive scraps and wild adults will find it within days. It's free, but only works where there's an established population and warm weather.

Once it's going, a colony self-perpetuates as long as you keep feeding it.

Harvesting and feeding off

The daily routine for an established bin is short:

• ◆Add fresh scraps (1 lb per 1,000 larvae as a rough guide)
• ◆Empty the harvest bucket of overnight pre-pupae
• ◆Check moisture and add dry bedding if it's soggy
• ◆Use harvested pre-pupae fresh, refrigerate them for up to about two weeks, or freeze for long-term storage

Pre-pupae are the most nutrient-dense stage and the standard form for animal feed. Live larvae work too if your animal prefers chasing active prey. If you'd rather buy clean, ready-to-feed larvae than run a bin, that's exactly what the black soldier fly larvae collection at my shop, All Angles Creatures, is for.

What to do with harvested BSFL

• ◆Chickens: BSFL run around 40% protein and chickens go nuts for them. You can replace 30-50% of commercial feed.
• ◆Reptiles: an excellent staple-rotation feeder for bearded dragons, leopard geckos, and most insectivores — and one of the few you don't have to dust.
• ◆Fish: tilapia, koi, and most freshwater fish take them readily.
• ◆Bait: pre-pupae make solid fishing bait.
• ◆Compost: surplus frass (the waste residue) is high-nitrogen compost for the garden.

Why BSFL are the no-supplement feeder

This is the part most new keepers get wrong, so it's worth being clear. Nearly every common feeder — crickets, roaches, mealworms, superworms — is phosphorus-heavy with a poor calcium-to-phosphorus ratio, which is why you dust them with calcium before feeding. BSFL are the exception. Their calcium is mineralized into the larval body itself, not just sitting in the gut, and at roughly 9,000+ mg/kg it already exceeds what dusting powder would add. So with BSFL you skip both the dusting and the gut-loading. The USDA's nutrient research has documented just how calcium-rich Hermetia illucens is compared to other feeder species (USDA ARS), and the FAO has covered their value as a sustainable feed insect in depth (FAO edible insects report).

Common problems

• ◆Bin smells bad: almost always wet, anaerobic conditions. Add dry bedding, cut back on food input, and make sure it drains.
• ◆Larvae escaping: pre-pupae climbing the walls looking for a dry pupation site. Either harvest them or improve the ramp so they self-collect.
• ◆No flies appearing: cold temps, no breeding adults, or no dry pupation spot. Warm it up and give them a dry cardboard corner.
• ◆Houseflies moving in: a dense BSFL colony out-competes houseflies. If you've got a housefly problem, your colony isn't strong enough yet — add larvae or give it time.

Bottom line

A small home BSFL bin turns kitchen waste into chicken feed, fish food, or reptile feeders with almost no labor. Setup takes under an hour, daily maintenance under five minutes, and a steady colony processes hundreds of pounds of waste a year. The real limit is climate — BSFL need warmth, so most of North America runs them seasonally. They're also the one feeder you can hand to your animals straight, no supplements required.

If you keep insectivores, pair this with my guides on how to gut-load feeder insects (for the feeders that DO need it) and how to store discoid roaches at home.