The length of the larval period, approximately 3-5 days,
was short enough so that the maggots migrated from the bags prior to
the collection of the bags. Visual observations indicated that the adult
flies oviposited in the refuse materials until the bags were filled and tied.
In many cases, the bags were filled rapidly and tied properly, but punctures
created by animals or objects provided ready entry for the ovipositing
adults and exit for the pupating larvae.