Cockroach Composting

This week in the Flog:

  • Article 1 of The Unconventional Composting Series
  • This week: Cockroach Composting!

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.

Why are cockroaches great composters:

  • 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.

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.

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.

Why I like it, and how to do it

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!

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

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.

Cockroach Composting - Part 1

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

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.

Cockroach Composting - Part 2

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

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.

Cockroach Composting - Part 3

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

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:

Cockroach Composting - Part 4

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

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:

Cockroach Composting - Part 5

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.

Cockroach Composting - Part 6

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

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).

Cockroach Composting - Part 7

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

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.

Cockroach Composting - Part 8

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.

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.

  • Nancy Collins

    Amused by your egg-carton cockroach condo! How prolific they are!

    What keeps the roaches from escaping out the top? Do they just love it in their cage so well that they have no desire to leave?

    Ia your watering system is 2 soda bottles together? Or did you buy it fully made?

    Thanks for the idea.

    • Patrick

      Heh, I had to note below, I forgot to mention this species doesn’t climb! Any plastic or glass surface is fine. The males have wings but can’t fly up.

      I bought that watering system fully made, it’s a chicken water I just added the pebbles so the roaches don’t drown – they drown if you just put a normal water bucket in there. I should have saved the $ and just recycled soda bottles though thats a good idea, thanks!

  • What about outside temp.I live in minnesota and want to know if this works in the winter?
    Also can they be harvested for chicken feed or fish feed?

    • Patrick

      Temps there would be a problem. Getting them to breed in low temps is the problem, they like it above 70 Fahrenheit at least. You can use a little heat bulb in an aquarium and I bet that would keep it nice and toasty, or one of those reptile heater pads that sticks to the bottom of the aquarium, 1 or 2 of those would probably work and be less in the way.

      As far as feed, they are EXCELLENT. High fat and protein content, chitin from the shell is really healthy, etc. If you build up a decent size colony you can harvest lots every day – see the egg carton laid across the top in the pic? I just pic that up and shake it out a bit into the food bucket, get 50-100 roaches per day.

  • I like the idea of the cockys, it would be good food for chickens as well, keeping them in a drum would be a problem, they would be wanting to get out.

    • Patrick

      yeah, I noted that below, this species can’t climb so as long as the inside of your drum is smooth you’re good.

  • Doc G

    You forgot to highlight the species of cockroaches you grow are non-climbing, so even when (not if…) one occasionally escapes they do not really go anywhere.
    Doc G

  • Patrick

    Thanks for the feedback everyone. It has come to my attention I forgot to mention this species can’t climb!

    You can keep them in a tub or aquarium or anything with a smooth surface on the inside. Totes work great and they’re a great cheap alternative to the aquarium (I just used the aquarium since it was leftover from when Opi was small).

  • Dennis Miano

    Thank you very much for this great info phil…

    i am on the 1st day of the milk mixture for the lacto serum… imagine reading all your blogs in a single night… i didn’t notice that it is morning already… i really enjoyed it all.

    i am really interested in cockroach composting… i a from quezon city, philippines… where can i buy that kind of roach?

    hope i can find one soon… i am starting to make my own design for their new home =)

    • Dennis Miano

      my mistake… it is Patrick (mentioned Phil).

      must be the mornight effect =)

      • Patrick

        Hey Dennis,

        Glad you are enjoying our site so much!! Sign up for the blog if you haven’t yet!

        Best place to find roaches here in the Philippines is you can find everything there, I love that site. Just text the people who put up the ads, schedule a meetup and buy your roaches. Make sure you use a glass or smooth plastic enclosure so they don’t escape, then you’re good. Look for one of these two species: blatta lateralis, or dubia. either roach will do, but I prefer blatta lateralis (lats). Also called turkistan roach, they are super easy and breed fast.


  • Chiliman

    Hello Patrick,
    I’d like to produce Insect Frass by myself because it’s so expensive. The Insect Frass from is made of excrement of herbivore insects, so it’s not exactly the same your cockroaches produce. Or is it not much different as you feed only some meat and bones? I need the repelling effect from this stuff because my vegetables are under attack. I use Diatomaceous Earth and it’s good, it helps but it can only reduce the grasshoppers and flying insects. To be specific does the cockroach poop produce Chitin? Copying from the organicsolution website:
    “What does Chitin do for plants?
    A: Chitin triggers a plant’s immune-response-system causing the plant to defend itself from pests and pathogens. Chitin is a natural biopesticide, and is known to kill root-feeding nematodes and their eggs, and fungal pathogens in the root zone. When plants sense Chitin in the vicinity, they think they are being eaten by insects, so the plant protects itself by strengthening its cell walls, produces more chute biomass (stalk and leaf material) and excretes secondary metabolites to ward off pests and pathogens”
    Will I get this effect from cockroach poop too?
    I’m located in Thailand so the climate isn’t much different. I guess you put your aquarium box in the shade. Is there any health risk for humans from bacteria of the cockroaches and if how can it be avoided?
    I searched on the internet how Insect Frass is made, what insects to use etc. but couldn’t find anything. Did I overlook something?
    Greetings from Patong Beach, Phuket!

    • Patrick

      Hey Chiliman,

      Great stuff there. I’ve actually done a ton of research on chitin and chitosan and formulated, based on many science journal articles, a great recipe for producing chitosan. A few notes from your questions:

      1. “frass” is generally used in place of “poop”. Normally when people talk about insect frass, they are referring to the insect’s poop. So in that way, any insect can be used, you are just collecting their poop and using that as ferilizer. Sometimes frass is used to refer to all the insect’s leavings like poop, shed exoskeletons, etc. In this case there will definitely be chitin in there – the exoskeletons are a super rich source of chitin.

      2. Chitin is found in crustacean shells like crabs, in fungal hyphae, and also in insect shells. As insects grow they shed their exoskeletons periodically, and those are excellent sources of chitin. Chitin has a ton of functions for plants as you mentioned, so any insects you cultivate and harvest the bedding from, will be great sources of this.

      3. Chitin is the precursor of chitosan. Chitosan is much more beneficial to plants and I think much more effective for the purposes you are after. Unfortunately nature isn’t good at breaking chitin down into chitosan, ideally you would do this using sodium hydroxide (lye). That’s a little intense though.. just compost the harvested bedding before you use it, and that should result in some chitosan making it into the application.

      So basically – grow whatever insects you want. After awhile, harvest the bedding which will contain their feces as well as shed exoskeletons and such.. Compost that, then apply to your plants as topdressing or in compost tea foliar spray.


      • Chiliman

        Patrick, you’re a treasure trove for me and for others too. Thx so much for replying quickly and so professional, I salute you!
        So the poop & pee, the exoskeletons and their dead bodies (died of age) not qualify already of being the desired material but it has to be composted. This would mean water the stuff and turn around (being aerobic) for a month or so? Composting alone or throw it into the compost pile? The stuff from organicsolutions is composted too? Not questioning your authority, just asking…
        Would an old fridge do the job as a cage for the cockroaches (Blatta lateralis) or could this species climb out?
        Actually I wasn’t 100% right that I didn’t find anything, I saw at that meal worms are used. Could meal worms and cockroaches being used in the same box? Or red wigglers added? Last question, are there any health risks regarding cockroaches as they’re said to spread diseases? Thx again Patrick!!!

        • Ron

          I use superworms and regular mealworms to make my frass. I don’t breed them in the same container though. What I like to do is wait till I start seeing dead half eaten larvae and beetles. That tells me that the larvae are at least digesting some chitin and “I hope” producing the enzymes chitinase and or chitosan. I then add the frass and dead insects to my worm bins with each feeding. I also add the frass directly to the garden and in some foilar feeding Applications. With so many introductions of chitin in different stages, I think that the plants get what they need in terms of fertility and insect repelling properties. At some point I will add crickets and bsfl compost and exoskeleton materials to the mix. Ultimately though, I feel feeding these insects to chickens and using the poop as fertilizer is the best method for getting the right enzymes into your soil. I just need some chickens.

          • Patrick

            Awesome post Ron, those are awesome methods. I like them because they are natural ways to get the chitin, and probably some amount of chitosan, to your plants.

        • Chiliman

          Sorry, I overlooked that you already described the composting process in the black plastic bag…
          In what ratio do you mix the frass with compost?
          Best greetings!

          • Patrick

            Hey Chiliman no worries. Ummm depends how strong you want your compost. That batch I made, the roaches had been living on it for more than 6 months. I had half a catfish buried in their frass that got digested down to nothing by the microbes there. It was super strong. It’s less a rule than just your feeling. If your bedding is only 1 month old (roaches only lived on it 1 month before changing) you could use it directly. If it’s older like mine was, you can mix much lower ratio with compost.

        • Patrick

          Hey Chiliman,

          Sorry for the late reply, it’s been a busy few weeks here.

          I’m not sure if the organicsolutions stuff is composted, but most likely not if they are just selling chitin. No need to compost if it’s just chitin, you can just harvest the shells. But in my view it’d be better to process the chitin somehow, to make it more bio-available.

          Blatta cannot climb smooth surfaces, either plastic or glass. However you’ll want to make sure there aren’t seams or cracks where they can get a foothold. I’ve found as long as all the walls are smooth, they can’t climb.

          Yep you should be able to use mealworms and/or red wigglers in combination with the roaches, that shouldn’t be a problem at all.

          Nope, no health risks with roaches that you buy from the store, unless the store has been practicing unsanitary conditions. Remember it’s not the roach itself that is the source of germs – it’s just that roaches in the wild typically hang out in horrible conditions, then act as a vector when they travel, carrying germs and such that they picked up, to new places they visit. Store-bought roaches should be totally fine.

          Ok I think that’s all of them. Sounds like you’re having fun!


          • Chiliman

            Great info Patrick!
            No health risk – very good. What you say is pure logic, I was blinded by “common knowledge” that cockroaches bring disease…
            I called a butterfly & insect garden (kind of an insect zoo) here in Phuket but they don’t have Blatta Lateralis. Also online impossible to find in Thailand. Is it possible to order from the Philippines? I found a Filipino website but I didn’t understand much as the blog wasn’t in English. I found online stores in the US and UK but I wonder if they survive such a long trip.
            When I think of the Phillipines pool billirds god Efren Reyes comes to my mind. I saw him live in tornament 1981 in Reno, Nevada and again in 1989 in Charlesville, 30 km from Chicago. What a humble guy and a hell of a player!


  • Mario Maldonado

    Great work, who could thought on this kind of compost, one question, how do you get the compost after is done, what do you do with the roaches in the mean time, thanks.

    • Patrick

      Hi Mario,

      the roaches like hiding in their egg cartons, so I remove the cartons in one block and put them in separate bucket while I clean the tank. Then I remove all the bedding and change it with fresh bedding. Works great! Though if you’ve read my lacto story, you can see some disastrous results if you don’t treat the bedding right.


  • Ellen

    A few questions. I browsed a bit and didn’t see answers. Hopefully I looked hard enough.

    1. Is he poop hot as far as fertilizer goes?

    2. Is there any risk of infestation if let loose live for chicken feed when we have winter freezes below 20F?

    3. What is the apication rate for vegetable gardens?

    I know if you Google AARON PAULING he sells them. I was just about to order before I found this site. Aaron Pauling doesn’t have this info on his site but he does ship roaches and he sells manure on request.

    • Patrick

      Hi Ellen,

      Great questions. Let me answer to the best of my knowledge.

      1. Yes I think the poop is very hot, it comes out in tiny concentrated pellets. Though I’m not really sure on this as I haven’t had it tested.
      2. I suppose there is in your house but not the wild.
      3. I would use the poop like any compost, maybe a bit more sparingly than normal compost as I think it is stronger

      You should order them and start it up, great way to get rid of kitchen scraps. Let us know how it goes!


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