Adults are large flies with a metallic blue or green color and are twice the size of a house fly (about 1/4-1/2 inches long).
These flies are common in populated areas and are particularly abundant near such places as slaughterhouses, meat-processing plants and garbage dumps. Blow flies will eat anything and will use their sponging mouth parts to do so. They will use regurgitated fluids to turn their food into liquid and then proceed to feed.
Eggs are laid on meat or dead animals, although they may be placed in decaying vegetable materials when meat is not available. They are frequently found in meat scraps or wastes contained in garbage. Garbage cans are the most important sources in urban areas. Single cans have produced more than 30,000 flies in one week. Newly hatched larvae feed for a short time on the surface of the decaying material on which the eggs where laid and then burrow into the less decayed material underneath. When mature, the larvae leave the food materials and burrow into the ground and pupate.