Where do filth flies commonly reproduce?

Filth flies, also known as house flies, thrive in environments where there is a rich source of organic material for their larvae to feed on. This is why manure, garbage, and rotting organic matter are ideal for their reproduction. The decaying material provides not just sustenance but also the warmth and humidity necessary for their eggs to hatch and for larvae, or maggots, to develop.

While some flies may occasionally be found in moist soil or other environments, their most significant breeding grounds are directly associated with decomposing organic waste. Clean kitchens are not conducive to their reproduction since they lack the necessary decaying matter, and while water bodies might support other forms of life, they are not a primary environment where filth flies reproduce. This makes the location of manure, garbage, and rotting organic matter the correct answer, as it directly correlates with the life cycle and habits of filth flies.