Black soldier fly bin
Recently we decided to take on a new project and build a black soldier fly bin. The black soldier fly larvae is a fantastic composter and will eat about any organic matter. The larvae are terrific food for the chickens. They have a high fat and protein content and chickens absolutely love them. They will be fed scraps and spent barley we can get for free from a nearby brewery. After the initial cost of the materials to build the bin and the BSF larvae starter pack, we will be getting free chicken food.
Why black soldier fly instead of worms?
We looked into other composters like mealworms and just your standard worm. Here in NW Missouri, we can see 100 degree weather and periods of drought during our summers. Those two things are hard on regular worms. The BSF likes the heat.
Ultimately the deciding factor for us was when we learned we didn’t need to dig or sort out larvae to feed to the chickens. When they are ready to pupate from larvae to a fly they “self-harvest”. That is, they will leave the compost area to seek the soil to begin the transformation to a fly. With a correctly designed bin the larvae are going to be in a container after self-harvesting and ready to be fed to the chickens. We won’t have to touch them.
Picking a black soldier bin
We spent a fair bit of time watching different YouTube videos of the different bins available for the black soldier fly. There are commercially available bins made from plastic and home built models from plastic and wood.
Some of the plastic bins had a small hole for the larvae to drop through when self-harvesting. In several of the videos, I noticed the hole became partially blocked. Larvae were finding alternate routes from the bin and didn’t make it into the collection container. The ramp for the mature larvae to crawl was more complex than the simple wooden version we saw.
The wooden bins were larger and would easily accommodate more BSF larvae. I liked the simple collection system on them. Ultimately we elected to go with a wooden bin and to build our own. We bought some black soldier fly bin instructions through a website that also sells larvae. This bin was in one of his many BSF videos and the design was simple and looked easy to build. You can see the one we liked in this video.
Assemble and paint the black soldier fly bin
We pre-cut all the pieces for the bin on the table saw and assembled the bin near the chicken pen where it will ultimately be placed. The assembly was pretty easy and straightforward. The ramp for self-harvest did give me the business, but we got it done. We used a little caulk to seal up any small gaps to keep the larvae in the bin.
In this picture, you can see the bin and the ramp for self-harvest of the mature larvae. They will crawl up the ramp and be directed to the hole.
The BSF larvae will fall through this hole and into the bin below. We used some cheap plastic food storage bins from Walmart. You can see the food storage bin in this photo.
After applying several coats of an exterior white latex paint to the bin we added about three inches of sawdust to the bin. This will keep the larvae off the bottom of the box to prevent them from going through the drain holes.
Some pieces of cucumber were added to provide the larvae that arrived in the mail from NW redworms. Here you can see the prepared bin with food and larvae.
Paint to protect the black soldier fly bin
Because the black soldier fly bin is made with plywood it would not last long if left unprotected from the elements. We want to make this ban last more than a couple of years, therefor we decided to paint it. We went with a cheap can of exterior latex from Walmart and applied several coats. It will seal that plywood and help it last several years before needing replacement. Here is what the completed black soldier fly bin looked like after applying paint.