Blatticomposting is the practice of converting human food wastes into compost using roaches. You can consider it a competitor to vermicomposting, which uses worms.
Roaches have a bad reputation in the animal kingdom. We consider them home invaders and pests, a sign of filth and decay. However, only 0.3% of roach species are human pests; the other 4985 or so species cannot survive easily in human homes and live in a variety of regions as detritivores. In other words, they’re functional niche, like worms, is literally composting.
In the last few years, the University of Michigan, Dearborn has been experimenting with blatticomposting on a large scale and how it compares to vermicomposting. They are specifically experimenting with Eublaberus species of roaches, which are cave species that subsist in the wild on bat guano and anything else they can find. The university’s initial observations indicate that there are some major potential advantages to roaches as composting agents; they reproduce more rapidly, are more tolerant of drier conditions which helps prevent mold, are more tolerant to overcrowding, and consume a much higher quantity of food waste per day per roach.
Horseshoe Cab Roach (Hemiblabera tenebricosa) eating a piece of banana
These advantages mean faster conversion to usable soil (roach droppings, called frass, are one of the most efficient fertilizers in the world), less mold, and no stink. As an added advantage, there is growing evidence that roach feet have antibacterial properties, so they actually leave the world a little cleaner with every tiny step.
Blatticomposting is also popular, already, in New York City, where Madagascar Hissing Cockroach males have been living in compost bins since before 2017, when we started selling roaches and customers in NYC started asking for replacements for their previous compost roaches.
We carry two species of Eublaberus roaches, and they have slightly different qualities. The orange head roaches are also known as skunk roaches, and smell a little bit like marijuana. They live well in a semi vertical setting with egg cartons to help make additional space. They tend to be very thirsty colonies and get dry faster than you expect; this is partially because there are usually two or three times as many roaches as you can see on top. These roaches tend to dive when you open the lid, but not to the extent of their cousins.
The other species we carry is the ivory head roaches. This subspecies does not smell and thrives in a wide shallow bin with an edible substrate like coco fiber. The roaches dive directly under the surface when you open the bin and the surface ungulates. They also reproduce quickly, but seem to need less moisture.
Other roaches that are worth experimenting with include:
Giant Cave Roaches: this species eats a lot because they are very large. They need quite a lot of vertical space and complete darkness to breed, so their colonies are easy to control.
Hissing Cockroaches: There are several species. They are all fairly easy to sex if you have adult and sub adult roaches, as the males have horns. The most common variety, G. portentosa, reproduces readily at room temperatures. The next most common, G. oblongonota, generally reproduces when temperatures are closer to 85 degrees fahrenheit. There are some fancier versions, like tiger hissers, that could also work. The disadvantage with hissing cockroaches is the nymphs don’t tend to dive into the soil the way the other roaches do, and are more likely to escape into your home. This sounds terrifying, but thus far the worst that has happened in our home is entertaining the cats; they dry up and die when exposed to the human home.
Pycnoscelus roaches: The two most common species are P. nigra (Shadow Roaches) and P. surinamensis (Surinam Roaches). They are capable of becoming home invaders only in warm, humid regions, like Florida, where they are already present in the wild. However, in most regions, houses are much too dry for them to survive, let alone establish themselves. They are worth experimenting with because they are very small, but instead of flying, they dig when their containers are opened. They are parthenogenetic and reproduce extremely rapidly, as the species has no males. A small box of shadow roaches can eat itself out of house and home, including the coco fiber substrate in as little as a month, if not regularly fed.
Another advantage of Blatticomposting in the reptile world is you can always make sure you choose a species that is useful to you. Do you have a bearded dragon? You should try hissers or an Eublaberus species. Do you have a chameleon or a crested gecko? Maybe give the Pycnoscelus roaches a go. There is no reason your composting animals can’t double as a food source.
As a final note: don’t hold back on the bones and eggshells! Your roaches, even the composting ones, need a source of calcium to remain healthy.