Rat-tailed Maggot
Scientific Name: Eristalis tenax (most common species)
Order & Family: Order: Diptera (Flies), Family: Syrphidae (Hoverflies)
Size: Body around 20mm (0.8 inches) long; the 'tail' (breathing tube) can extend up to 150mm (6 inches) when submerged.
Natural Habitat
Typically found in stagnant, oxygen-depleted water such as manure lagoons, sewage, liquid compost, and rotting organic slop. They may migrate to drier areas to pupate.
Diet & Feeding
They feed on decaying organic matter and bacteria found in stagnant water and liquid waste.
Behavior Patterns
The larva uses its long, snorkel-like tail to reach the surface for air while its body remains submerged in polluted muck. When fully grown, they crawl out of the semi-liquid environment to find a drier place to pupate, which is likely what is happening in this photo.
Risks & Benefits
Generally harmless to humans; they do not bite or sting. In rare cases, accidental ingestion can cause intestinal myiasis, but this is uncommon. The adult form (hoverfly) is a beneficial pollinator.
Identified on: 2/21/2026