While there were many species of mites, springtails, and other tiny bugs in our bin, we were missing predators. I ordered a few million nematodes (a kind of tiny roundworm) by mail. Within a few weeks (long enough for the adult flies to die off and their larva to have been eaten) we had a fly-free bin.
All multicellular organisms use cell division for growth and the maintenance and repair of cells and tissues. Single-celled organisms use cell division as their method of reproduction. Somatic cells divide regularly; all human cells (except for the cells that produce eggs and sperm) are somatic cells.
In single-cell organisms, mitosis is the only form of cellular reproduction. One round of mitosis yields two genetically identical cells. In bacteria, this process results in an entirely new, independent organism. This is classified as asexual reproduction because it does not require sex for the creation of new organisms. In multi-cellular organisms, like ourselves, mitosis only occurs in somatic cells, which comprise all cells in an organism excluding germ cells.