Cockroach Composting

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For most people like you and me, composting serves two main purposes – eliminate food wastes biologically rather than wastefully(landfill), and create nice rich nutrients for plants. You can use all kinds of methods to accomplish those goals, and this article is a great example of that. Cockroaches! Yes, cockroaches are incredible composters. Truly amazing, they will eat anything and everything you put in there, reproduce like crazy, and have virtually NO SMELL. I know it’s shocking to think of cockroaches as being a clean detritivore, but it’s true.

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Why are cockroaches great composters:

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• Extremely durable (hard to kill)

• Eat almost anything – coffee grounds, meat, dairy, veggies, fruits, grains, nuts, etc etc

• Reproduce very quickly

• Super low maintenance

• Eliminate waste efficiently (produce few nutrient dense droppings per large food intake)

• Very clean – little smell

 

I have a Bearded Dragon, Opi, who originally got me into the cockroach thing. Bearded dragons are voracious eaters, and besides the cost I just didn’t want the hassle of going back to the store every week. After doing some research I found roaches an excellent solution to this issue. 

The species of roach I got is a standard feeder species, Blatta lateralis, you can buy them in many pet stores or order online. I ordered off a craigslist type site local to the Philippines, went down to the station and met a guy with a bag of roaches. 

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Disgusting. I agree. I grew up in the country, I love reptiles, amphibians, arthropods, all manner of creepies, but roaches are just disgusting. However! After raising them I can say they really aren’t so bad – I think it’s the no smell thing that makes me feel better.

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Anyway, after the meet-up for the bag of roaches, brought them home and a little while later, thriving colony, everyone happy, Opi diving into mounds of the things quite happily, etc etc. 

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Why I like it, and how to do it

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First why I like it. It requires cleaning the whole setup once every 6 months or so. That is after putting all kinds of food in every single day – dog food, people food, nasty moldy food, not-even-food food, whatever. There is NO smell from 2 feet away and I only have to clean the tank every 6 months? I can throw all my scraps in it no matter what they are? It produces insane compost for the garden? Sign me up!

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I cleaned out the cockroach composter(aquarium for now) today so I took the opportunity to grab some pictures. 

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Here is the overall setup before cleaning. This is after about 6 months of doing nothing except adding food and changing the water every few weeks.

The tank before I cleaned it. You can see the feeding area has some bones around.

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Cockroaches are prolific breeders. This species lays egg cases(ootheca) at an astonishing rate. Check out the substrate surface before cleaning it – each of those egg cases contains 20-30 eggs, gives you an idea how fast the colony can grow. You can also see some chicken bones, fish bones, a little stick of bamboo – leftovers from feeding. No need to remove these things as they will be great in the compost pile or garden.

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Close-up of the substrate…except you can’t see the substrate for all the egg cases.

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The bin attracts various creatures. This type of beetle(some type of darkling beetle I think) invaded and went crazy in there, there are almost as many of them as there are roaches. The beetle larvae burrow around in the substrate and eat up everything the roaches don’t and they seem to get along fine so whatever. Don’t fight nature if you don’t have to! As unconventional farmers, we are working with nature as much as *humanly* possible, haha.

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The invader – I think a darkling beetle species. They reproduce like crazy but get along great with the roaches so whatever.

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The bin also attracts larger creatures though, such as sparrows and geckos. I finally had to put a lid on the bin to keep the sparrows (I have roaches to spare, as opposed to my beautiful sprouts they trashed on the other balcony) out because they were trashing it trying to get at the roaches. I love attracting nature to the balcony, I was sad I had to lock the birds out but at least the geckos can still get in and get their fill. The birds came a few days and then figured it out:

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The predators. I finally covered the top of the cage because the birds were tearing it up a bit.

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After 6 months the bedding is insanely rich over under the food area. It is moist and thick, full of nutrients from 6 months of cockroach frass and decomposed organic matter. You can see the darkling beetle larvae, pupae, and a few adults:

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Look how rich that soil is! It used to be coco coir but now it’s unrecognizable. There are some egg cases and beetle larvae visible too.

The darkling beetles even core out the chicken bones so they end up being hollow – perfect home for microbes and roots. With the roaches temporarily in a black plastic garbage bag (new egg-carton home goes in first, then old home gets shaken out so all the roaches end up in the bag with their new home), the bin gets a cleaning and then new bedding – a thick layer of coco peat. This is utilizing the deep bedding principle core to animal raising natural style – but that’s a separate topic altogether.

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After cleaning, a thick layer of coir goes down first. this is how the last stuff started.

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Now the new roach home (egg cartons) comes out of the black plastic garbage bag and into the bin. The roaches naturally seek the dark safety of the cartons so they are easily moved inside the cartons(which are all glued together for stability).

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The roaches in their new home (egg cartons glued together) in their newly cleaned home (aquarium)

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Last bit since it’s evening now and they get fed each night – food time! The staple when there are no veggie/meat trimmings is fermented dog food. I put the dog food in a sealed plastic container with some lacto, it ferments for a few days then I feed that to them. They just love the stuff. Doesn’t take much to feed the colony as you can see here.

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Feeding time – the lighter beige pieces there are bits of fermented dog food – the roaches love it and it keeps them healthy and growing fast

What a beautiful system… the cleaned out bedding is an incredible nutrient source. It goes into a black plastic bag and gets sealed to kill off the egg cases and beetle larva. Lacto solution is added to facilitate decomposition in the anaerobic conditions. After a few weeks its ready for use! It’s amazing, I pulled out corn cobs that just disintegrated in my hand when I picked them up. The level of decomposition is crazy – only bones left, and not even that many of them considering how many went into it. I’m keeping this compost handy for use in the garden later – it will get mixed with traditional compost – it’s too strong and valuable to waste just by itself.

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You’ve heard of vermicastings – worm compost. And Bokashi compost – fermented kitchen waste. You might even have heard of BSF compost – fly larva compost.  Well, now you’ve learned about cockroach compost! Spread the unconventional word about this weird freaky compost method that works so effectively.