The black soldier fly composter
The larvae harvest themselves by crawling up a ramp into a bucket. It is the cleverest passive mechanism on this site.
What it is
A bin that farms black soldier fly larvae on kitchen and garden waste. When mature, the larvae instinctively crawl upward and away to pupate — so you give them a 35-degree ramp that dead-ends over a bucket, and they deliver themselves.
The numbers
- Larvae run roughly 40% protein and 30%+ fat on a dry basis — genuinely good chicken feed.
- They process waste fast, and they outcompete houseflies in the same bin, which is a real sanitation benefit.
- Working temperature is roughly 75–100°F. Below about 60°F they stop.
Why it's here
Self-harvesting is a rare thing in any system: the output walks out of the machine and lands in a bucket. No screening, no sorting, no separating. Few things in this whole file are that elegant.
The automation angle
A temperature probe is the only instrument that matters — the colony's whole performance is a function of bin temperature, and watching it tells you when the season really starts and ends.
The catch
It's a fly farm, and it's seasonal in the north. They go dormant or die in the cold, so above roughly the 40th parallel it's a summer system unless you heat it, which changes the economics completely. Site it downwind, and accept that some fraction of visitors will not find it charming.