Just about everybody are aware of fruit flies and drain flies, and also common house flies; however, there is a fly that is often mistaken for a fruit fly because of its smaller size, and that is the coffin or humpbacked fly.
Coffin flies are usually about 1/16th to 1/8th inch in length, and the upper section of the rear leg is flattened and wide. Another identifying characteristic is that their back is shaped like a hump (humpbacked fly).
Coffin flies prefer to be in the caskets where they lay their eggs and the larvae can feed on the decomposing body. Their life cycle lasts about 2-6 weeks. Female coffin flies generally lay about 500 eggs in a lifetime. After feeding in the coffin, the larvae pupates, forming a cocoon in the casket, and finally emerges as an adult.
Coffin flies are susceptible to carrying and spreading diseases, because of what they are feeding on, and they are very unsanitary creatures. A number of mausoleums allow the infestations of coffin flies to happen, and a lot of the managers of these places are not forthright in telling their employees or visitors where the flies feed. Frequently, they will mislead families and their workers, telling them that the fresh flowers bring the flies; but if that were true, the flies would be infesting flower shops, not mausoleums.
If you visit a mausoleum and observe the coffin flies, register a written complaint with the mausoleum, in addition to with the Funeral Consumers Alliance, the Health Department, and the Attorney general. With regards to a Catholic Cemetery, register a complaint with the church and the local bishop.