Rat-tailed maggot

Scientific Name: Eristalis tenax

Order & Family: Order: Diptera, Family: Syrphidae

Size: 20 mm to 35 mm (including the long tail-like siphon)

Rat-tailed maggot

Natural Habitat

Stagnant, organic-rich water such as drainage ditches, sewage pits, or farm runoff where oxygen levels are low.

Diet & Feeding

Larvae feed on decaying organic matter and bacteria found in stagnant water; adults feed on pollen and nectar.

Behavior Patterns

The long 'tail' is actually a breathing tube (siphon) that allows the larva to breathe air while submerged in oxygen-depleted water. They eventually crawl to drier areas to pupate into hoverflies.

Risks & Benefits

Generally harmless and beneficial as pollinators in adult form. Very rarely, they can cause accidental intestinal myiasis if ingested via contaminated water, but they do not bite or sting.

Identified on: 12/30/2025