Pest profile

Drone Fly and Rat-Tailed Maggot

Eristalis tenax · Diptera: Syrphidae[2]

Rat-tailed maggots in a pet bowl, tire or manure pit become drone flies, bee-like flies that are important pollinators.[1]

Rat-tailed maggot, the drone fly larva, a pale segmented maggot with a long tail-like breathing tube
Rat-tailed maggot, the drone fly larva, a pale segmented maggot with a long tail-like breathing tube. (c) Wendy Bailey, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Larvae carry a long tail-like breathing siphon that can be several times the body length, hence rat-tailed maggot.[1]
  • Adults resemble honey bees and visit flowers; they're important pollinators.[1]

Look-alikes

Look-alikeHow to tell them apart
Honey beeAdult drone flies mimic honey bees; old tales of bees arising from carcasses likely came from drone flies laying eggs in them.[1]
Hover fliesThe drone fly is a syrphid, related to other hover flies.[1]

Where it lives

It occurs on every continent except Antarctica; in the U.S. it ranges as far north as Alaska.[1]

US map: public records from 46 states since 1990 (GBIF).

Biology and life cycle

Larvae live in highly polluted water, such as manure lagoons and holding pits.[1]

Damage and signs

  • It's usually not a serious pest, but larvae can migrate in large numbers from livestock waste sites in summer.[1]

Health risk

UF/IFAS describes it as a nuisance at most, not a health threat.[1]

Control

Sanitation

Keep manure lagoons and pits in good condition so manure doesn't break the water surface.[1]

Common questions

What are the maggots with long tails in standing water?
Rat-tailed maggots, larvae of the drone fly.[1]
Is that bee a bee?
Possibly a drone fly, a honey bee mimic that doesn't sting.[1]

Sources

  1. University of Florida IFAS Extension (Featured Creatures), “Drone Fly, Rat-Tailed Maggot, Eristalis tenax (EENY-445).” edis.ifas.ufl.edu/publication/IN809 (accessed 2026-10-06)
  2. iNaturalist, “Eristalis tenax taxon page (order and family).” www.inaturalist.org/taxa/55719 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.