The other extreme to regular removal is to allow manure to accumulate for long periods of time.
If manure is regularly compacted and trampled by large livestock (such as in feedlots), the medium will be unsuitable for fly breeding.
In poultry production (caged-layers and breeders) manure is often allowed to accumulate for a year or more. In this situation, if the manure dries sufficiently, fly breeding will be minimal.
Accumulated manure is a habitat for many species of predators and parasites which attack the eggs, larvae, or pupae of flies and significantly aid in reducing fly numbers.
With accumulations of manure, the degree of airflow and protection from moisture (rain, drainage, and leaking animal waterers) become of major importance because the drier the manure, the less suitable it is for fly breeding.
