Blatticomposting is a new technique that uses cockroaches to convert human food wastes into compost. Of the 4000 or so species of cockroaches, less than 15 are pests of human dwellings. These species give cockroaches overall a bad reputation; all other species of cockroach are harmless, living outdoors and feeding on leaf litter, fruit, and other organic materials. They play an important role in food chains, as many predators feed on them. In tropical areas, cockroaches play a huge role in nutrient cycles, eating wood and leaves, turning them into soil. Termites, which are actually a type of cockroach, even help prevent wildfires in scrub and desert habitats by eating dead, dried wood that collects on the ground. As the importance of cockroaches has become clearer, exploration into cockroaches for human uses has only just begun.
The genus Eublaberus is of particular interest to humans; these cockroaches live in bat caves where they feed on bat droppings (guano) and anything else they happen to find. The young cockroaches, called nymphs, form dense colonies on the cave floor that can be several inches thick. In captivity, they are easy to care for and breed using very simple and inexpensive supplies. Their hardiness, tolerance for crowding, and big appetites make them the ideal candidate for blatticomposting experiments.
Although vermicomposting, or using worms to compost, has been used to deal with human food wastes, it has several drawbacks. Worms need moist conditions to survive, but many pest bugs also enjoy the moist conditions of the worm bin. Fruit flies, their larvae, and mites can all become established in a worm bin, creating a nuisance for humans. Cockroaches tolerate much drier conditions, which prevents pests from infesting a compost bin. Worms also do not eat much; a colony of cockroaches can consume an apple in less than a day, whereas a colony of worms takes much longer to eat the same amount of material. Worm bins may also produce an odor, as uneaten compost scraps begin to mold. As noted before, cockroaches consume material much faster, which means there is nothing to produce an odor or for mold to grow on.