Rat-tailed maggot

Scientific Name: Eristalis tenax

Order & Family: Diptera: Syrphidae

Size: 20 mm (body) to 100 mm (including tail)

Stagnant water rich in organic matter, such as lagoons, sewage, or manure pits

Decaying organic matter and bacteria via filter feeding

Uses its long respiratory siphon (tail) to breathe atmospheric air while submerged in low-oxygen environments

Beneficial as pollinators in adult stage (drone fly); can rarely cause accidental intestinal myiasis in humans if contaminated water is ingested

Identified on: 5/22/2026