Rat-tailed maggot

Stagnant, organic-rich water such as sewage lagoons, farm runoff, and polluted ponds.

Feed on decaying organic matter and bacteria found in stagnant water.

Use a telescopic breathing tube (siphon) to breathe atmospheric air while submerged in low-oxygen environments. They pupate on land in drier soil.

Generally beneficial as adults (Drone flies) are important pollinators. Rarely, they cause accidental intestinal myiasis in humans if contaminated water is ingested, but they are not parasitic.