Rat Tailed Maggot: Essential Facts and Tips for Curious Minds

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Rat-tailed maggots are fascinating creatures found in stagnant water environments. They are the larvae of the drone fly, often mistaken for honey bees as they share similar characteristics. These tiny inhabitants serve as a vital link in their ecosystems, participating in the process of decomposition and providing a food source for various fish species.

Growing to about ¾ inches long, mature rat-tailed maggots have a unique feature: a long, tapered breathing tube, also called the “tail.” This extraordinary adaptation allows them to inhabit nutrient-rich, oxygen-poor aquatic environments. Ice-fishing enthusiasts are familiar with these creatures, commonly using them as bait – also known as “mousies” – for perch and other panfish. The wiggling tail is quite enticing to fish, often causing them to prefer mousies over other baits.

In addition to their ecological role, rat-tailed maggots have an intriguing history. Their presence in Biblical writings adds to their mystique, as they are believed to be the source of texts depicting honey bees emerging from dead animals. These intriguing creatures continue to pique curiosity, making them a notable subject in the natural world.

Rat Tailed Maggot Basics


Rat-tailed maggots are the larvae of the drone fly, also known as Eristalis tenax. They belong to the Syrphidae family, which mainly consists of hoverflies. A key characteristic of these larvae is their long, tail-like breathing tube, which can sometimes exceed their body length of ¾ inches.

Life Cycle

The life cycle of the rat-tailed maggot consists of four stages: egg, larva, pupa, and adult. Here’s a brief overview:

  • Egg: Female flies lay eggs near suitable habitats for their larvae.
  • Larva: The rat-tailed maggots feed and grow during this stage. They can extend their breathing tube to reach the surface when submerged in water.
  • Pupa: Larvae develop into a pupa, usually in drier habitats, before transforming into an adult fly.
  • Adult: Adult drone flies resemble honey bees and contribute to pollination.


Rat-tailed maggots are typically found in aquatic environments, such as ponds, ditches, sewage plants, and liquid manure. They often reside in areas with polluted water, as their breathing tube allows them to thrive in low-oxygen conditions.

Feature Rat-tailed Maggot Drone Fly (Adult)
Class Diptera Diptera
Family Syrphidae Syrphidae
Body Approx. ¾ inches long, with a long tail-like breathing tube Resembles European honey bee
Habitat Aquatic environments, often with polluted or low-oxygen water Gardens, meadows, open spaces near water sources
Role in Ecosystem Decomposer within wet, polluted habitats Pollinator

Key Characteristics of Rat-Tailed Maggots:

  • Belong to the Syrphidae family, mainly hoverflies
  • Long, tail-like breathing tube
  • Found in aquatic environments, often polluted water
  • Contribute to decomposition within their habitats

Physical Characteristics

Coloration and Morphology

Rat-tailed maggots are commonly found in various shades, including red, brown, and white. They have a cylindrical shape and horizontal folds running across their body. Rat-tailed maggots are distinguishable from other types of maggots by their long tail, adorned with flexible hairs.

Their key features include:

  • Red, brown, or white coloration
  • Cylindrical shape
  • Horizontal folds
  • Long tail with flexible hairs

Breathing Siphon

The standout characteristic of rat-tailed maggots is their telescoping breathing siphon, which resembles a tail. This siphon acts as a breathing tube, functioning like a snorkel. It extends from the maggot’s anus, allowing it to inhale oxygen in aquatic environments.

Key features of the breathing siphon:

  • Telescoping structure
  • Functions as a breathing tube
  • Resembles a snorkel
  • Extends from the maggot’s anus

Here’s a comparison table of rat-tailed maggots and typical maggots:

Feature Rat-tailed Maggots Typical Maggots
Coloration Red, Brown, White White
Body Shape Cylindrical Cylindrical
Horizontal Folds Yes Yes
Tail/Siphon Appearance Long, with flexible hairs Absent
Breathing Mechanism Tail-based siphon None (air-breathers)

Overall, the most distinct aspects of rat-tailed maggots are their long tail and telescoping breathing siphon, which differentiate them from common maggots.

Feeding and Predation

Feeding Habits

Rat-tailed maggots, the larval stage of drone flies, primarily feed on decaying matter in stagnant water. They are known for their ability to thrive in environments with high organic content. These maggots consume decaying plants and other organic materials, making them excellent decomposers.

Their unique breathing tube or “tail” allows them to respire while submerged in water, as they can bring it up to the surface to access air. This adaptation helps rat-tailed maggots maintain their consumption activity in oxygen-poor environments.


In their aquatic habitat, rat-tailed maggots face predation from various invertebrates, such as other aquatic insects and species that feed on larvae. Some examples of invertebrate predators include:

  • Dragonfly larvae
  • Predaceous diving beetles
  • Water scorpions

As the rat-tailed maggots transform into adult drone flies, they also become prey for predators such as birds and spiders.

Comparison of feeding habits and predators:

Features Rat-Tailed Maggots Predators
Habitat Stagnant water with high organic content Aquatic or terrestrial
Feeding Habits Decaying matter, plants, and organic materials Rat-tailed maggots, other insects, or small aquatic animals
Adaptations Breathing tube (“tail”) for respiration in low-oxygen environments Hunting strategies, specialized mouthparts, or web-building capability for spiders

This section covered the feeding habits of rat-tailed maggots, their adaptation to oxygen-poor environments, and the predators that feed on them during different life stages.

Distribution and Environment

Geographical Distribution

Rat-tailed maggots (Eristalis tenax) are found in various parts of the world, such as the United States and Africa. They were introduced from Europe around 1875 1. Their distribution includes areas with warmer temperatures for larval incubation 2.

Environmental Adaptations

These larvae have specific habitats and adaptations which help them thrive in their environment:

  • Habitat: They are known to dwell in lagoons, manure pits, cesspools, sewage lagoons, and stagnant water, where they can access decaying organic matter 3.
  • Pollution Tolerance: Rat-tailed maggots can survive in highly polluted water due to their unique breathing tube called the “tail.” This 1/2 inch long tube allows them to extract oxygen from the atmosphere while they remain submerged in oxygen-depleted environments 4.

Pros and Cons of Rat-Tailed Maggot Adaptations

Pros Cons
Adaptive in polluted environments Often associated with unsanitary conditions and potential disease vectors
Can survive in a relatively wide range of stagnant water habitats May be considered a pest in some environments
Unique breathing mechanism enables them to thrive in low-oxygen environments May not be well-suited for clean water sources or environments with high oxygen content

The Drone Fly

Appearance and Mimicry

The drone fly, also known as Eristalis tenax, is a species of hover fly often mistaken for a honey bee. It has a few key differences, including:

  • Larger eyes
  • Shorter antennae
  • Clear wings

This mimicry aids in their survival by discouraging potential predators who may avoid bees due to their stinging capability.

Honey Bee Comparison

Feature Drone Fly Honey Bee
Eyes Large, taking up most of their head Smaller, more evenly spaced
Wings Clear, unpatterned; Two per side Four wings, patterned veins
Legs Sticky, adapted for landing on flowers Fuzzy, with specialized structures
Abdomen Smooth without constriction (waist) Segmented with a narrow waist
Sting/defense Cannot sting; Mimicry as a defense mechanism Can sting, releasing venom

Pollination Role

Drone flies play an essential role as pollinators just like honey bees. Here are some shared pollination characteristics:

  • Both visit flowers
  • Transfer pollen between plants
  • Help plants produce fruits and seeds

Drone flies also have sticky legs that latch onto pollen from flowers, helping them pollinate plants effectively.

In summary, the drone fly, a rat-tailed maggot’s adult form, is often mistaken for a honey bee due to its similar appearance. Though they differ in physical features such as eyes, wings, and legs, they share an essential role in pollination as they transfer pollen between flowers.

Reproduction and Development

Egg Laying

Rat-tailed maggots, the larval form of the drone fly, begin their life cycle when the adult female lays her eggs. She primarily chooses stagnant water or decaying organic matter to provide a suitable environment for her offspring. Due to their preference for stagnant water, they can often be found in environments like:

  • Manure pits
  • Sewage treatment plants
  • Drainage ditches

Complete Metamorphosis

Rat-tailed maggots undergo a complete metamorphosis during their life cycle. This process involves several distinct stages, including:

  1. Egg: The life cycle begins with the female laying her eggs in stagnant water or decaying organic matter.
  2. Larva: The rat-tailed maggot, or larval stage, is characterized by a long breathing tube, or “tail,” which allows them to respire while submerged. During this stage, they feed on the surrounding organic material.
  3. Pupa: After the larval stage, the rat-tailed maggot forms a pupa, enclosing itself within a protective casing.
  4. Adult: The adult drone fly emerges from the pupal case, ready to reproduce and continue the life cycle.

Pupal Stage

During the pupal stage, the rat-tailed maggot undergoes a significant transformation. Here, it develops into its adult form, resembling a honey bee which is known as the drone fly. This stage can last from a few days to several weeks, depending on environmental factors.

Key Features

  • Egg Laying: Female drone flies lay their eggs in stagnant water or decaying organic matter.
  • Complete Metamorphosis: Rat-tailed maggots undergo four distinct life stages, including egg, larva, pupa, and adult.
  • Pupal Stage: The pupal stage is when the larval form transforms into its adult form, the drone fly.
Features Rat-Tailed Maggot Drone Fly
Habitat Stagnant water Various environments
Appearance Whitish with tail Resembles honey bee
Feeding Organic material Nectar and pollen
Reproduction Lays eggs as drone fly Mates as drone fly

Unusual Encounters

As Fish Bait

Rat-tailed maggots, besides their role in nature, have been used as fish bait. In the world of ice-fishing, they are called mousies, a popular choice for catching panfish. Their wiggly tails make them irresistible to fish, sometimes prompting anglers to use multiple maggots on a single hook for added attraction.

Myiasis Cases

Myiasis refers to the infestation of living tissue by fly larvae, including rat-tailed maggots. The maggots usually develop in warm temperatures found in tropical climates, infesting contaminated food or water (source). Consumption of contaminated food or contact with contaminated water can lead to intestinal myiasis. In some cases, maggots infest animal carcasses, creating a potential health hazard if they later come into contact with humans. Rat-tailed maggots can also be found in compost piles or feces, making it essential to maintain proper sanitation in gardens.

Features Rat-Tailed Maggot
Habitat Contaminated water, feces, compost, carcasses
Size 3/4 inches long
Use Fish bait
Risks Myiasis, intestinal infestation

In summary, rat-tailed maggots are frequently encountered in contaminated environments like garden compost, contaminated water, or animal carcasses. They can serve as efficient fish bait, but proper care must be taken to avoid unintentional health hazards, as they can cause myiasis and intestinal infestations if consumed or contacted unintentionally.

Scientific Interest and Research

Antibiotic Production

Rat-tailed maggots have drawn interest for their potential in antibiotic production. Researchers found that some larvae can be useful in extracting necrotic tissue and promoting wound healing, thanks to their excretions and secretions. These substances have antimicrobial properties that could be the basis for future antibiotic development.

Cesspool and Sewage Monitoring

Rat-tailed maggots also play a role in cesspool and sewage monitoring. They thrive in stagnant water, which can indicate pollution sources. By observing their presence in a location, scientists can gauge the level of water pollution, making rat-tailed maggots valuable bioindicators.


  • Inexpensive method
  • Environmentally friendly


  • Limited to specific environments
  • Not suitable for all pollution types
Method Pros Cons
Rat-tailed maggots Inexpensive, eco-friendly Limited, not suitable for all
Chemical testing Accurate, sensitive Expensive, harmful chemicals

Key Features of Rat-tailed Maggots:

  • 3/4 inch long body
  • 1/2 inch long tail, used for breathing
  • Thrive in stagnant water
  • Indicator for water pollution

Characteristics of Rat-tailed Maggots:

  • Whitish larvae
  • Honey bee mimic
  • Inhabit cesspools, sewage, and stagnant water
  • Attract scientific interest for potential antibiotic production and environmental monitoring

References and Resources

The Rat-Tailed Maggot is the larval stage of the drone fly, Eristalis tenax. It resembles a honey bee and is known for its unique, breathing “tail.”

Here are some notable characteristics:

  • Length: about ¾ inches long
  • Tail: ½ inch long
  • Habitat: stagnant water
  • Origin: Europe, introduced around 1875

Rat-Tailed Maggots are often found in stagnant water and can be present in large numbers. They are known as “mousies” in the ice-fishing world, where they serve as a popular bait for perch and other panfish.

The drone fly, Eristalis tenax, is a mimic of the European honey bee, Apis mellifera. It has been suggested that Rat-Tailed Maggots might be the source of Biblical writings depicting honey bees developing from dead animals.

In summary, some key features include:

  • Larval stage of the drone fly
  • Unique breathing “tail”
  • Found in stagnant water
  • Popular ice-fishing bait

Comparing the Rat-Tailed Maggot to other fly larvae:

Feature Rat-Tailed Maggot Other Fly Larvae
Length ¾ inches Varies
Unique Feature Breathing “tail” None
Habitat Stagnant water Various

Some advantages of using Rat-Tailed Maggots as bait:

  • Attractive to fish, thanks to wiggling “tail”
  • Can be used in combination with other baits


  • Primarily found in stagnant water
  • Maybe less appealing to anglers who prefer traditional bait

To learn more about Rat-Tailed Maggots and their role in the ecosystem, refer to the resources provided in the search results.


  1. Drone Fly, Rat-Tailed Maggot Eristalis tenax (Linnaeus)

  2. Maggot Infestation: Various Treatment Modalities

  3. Rat-Tailed Maggots and Moth Flies

  4. Drone Fly, Rat-Tailed Maggot – Eristalis tenax (Linnaeus)

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Drone Fly


Looks like bee but is a fly?
Perhaps you could answer what this fly is. It was found on pole bean leaves in Everett WA on August 24th mid morning. It’s been a cool summer and there is a well established garden that benefits from pollinators and poultry which attract the ugly house flies. But what is this guy? Thanks!

Hi Diana,
Your fly is a Drone Fly, Eristalis tenax, one of the Syrphid Flies in the family Syrphidae. We were surprised to read on BugGuide that this is an introduced species dating back to before 1874. The larvae, known at Rat Tailed Maggots live in stagnant water.

Letter 2 – Drone Fly


Subject: Is this a honey bee?
Location: Niantic,CT
November 1, 2012 3:02 pm
I see these in a field behind where I work in SE Connecticut. I assume it is a bee but can’t find anything that looks like it online and in guides. Thanks
Signature: scott knecht

Drone Fly

Hi Scott,
This Drone Fly is a convincing mimic of a male Honey Bee.  See BugGuide for a comparison photo.  The aquatic larva is known as a Rat-Tailed Maggot.

Letter 3 – Drone Fly from England


Subject: Masonry Bee?
Location: London, South East England.
April 11, 2014 1:15 pm
Hi! I would just like some clarification please! We noticed today that we had what appear to be bees flying in and out of a hole in the wall on our flat. We’ve lived here for years & it’s the first year we’ve noticed it. We’ve done googling and suspect them (it?) to be Masonry Bees but would love clarification as we’re both wimps when it comes to flying stinging things and would love to know where we stand for our own sakes but also that of the cats who seem to think the hole provides them with flying toys! And we obviously don’t want either to get hurt. It doesn’t look quite right for a masonry bee but doesn’t look like honey bees / bumble bees / hornets etc so we turn to your expertise! Thank you!
Signature: Tofu K

Drone Fly
Drone Fly

Dear Tofu K,
This is a harmless Drone Fly,
Eristalis tenax, and we were puzzled by your observations that is was “flying in and out of a hole in the wall,” and we learned something very interesting on Nature Spot where it states they can be observed:  “Virtually all year round. The female hibernates in buildings and crevices but will emerge on warm days in late winter, leading to it being seen in virtually every month of the year.”  Larval Drone Flies are known as Rat-Tailed Maggots.  More information is available on UK Safari.

Thank you for your prompt reply! I was expecting to wait a little while as the websites state you may have to.
Thank you for putting our minds at ease! I was concerned it was some beastly giant buzzing bee we were going to have to live with! And very “pleased” that they sometimes mimic bees – it means we’re not going completely crazy!
Glad you learnt something new about them too!

Letter 4 – Drone Fly


Subject: SO curious…

Location: Santa Cruz, Ca.
November 10, 2014 12:46 am
I found this insect drinking nectar with the honey bees in my garden. While my husband cannot see a difference between it and the bees, I see several differences. (If even sounds different when it flies.) It was spotted in Santa Cruz, California in early November. Please enlighten me!
Signature: Amber

Drone Fly (left) with Honey Bee
Drone Fly (left) with Honey Bee

Dear Amber,
You are quite observant.  We especially like your image of the Drone Fly,
Eristalis tenax, with the Honey Bee it mimics in the background.  Drone Flies are in the family Syrphidae and they do not bite nor sting.  See BugGuide for an excellent comparison image.

Drone Fly
Drone Fly

Letter 5 – Drone Fly


Subject: Beautiful Honey Bee Mimic
Location: 30 miles West of Topeka, Kansas
October 21, 2016 10:24 pm
I don’t need an I.D. For this Drone Fly. I just wanted to share a couple photos of this excellent faker.
It found me in N.E. Kansas, U.S.A., about the last week of September, 2016. Everybody I showed it to thought it was a honey bee.
Signature: Jeff from Kansas

Drone Fly
Drone Fly

Dear Jeff from Kansas,
This excellent Honey Bee mimic is a Drone Fly,
Eristalis tenax.  According to BugGuide:  “Introduced in North America prior to 1874.”

Letter 6 – Hover Fly: Brachypalpus alopex


Subject:  Fly in the forest
Geographic location of the bug:  Olalla, Washington
Date: 03/07/2018
Time: 09:00 PM EDT
Your letter to the bugman:  Hi. This fly was sitting on a coltsfoot leaf in the forest on a chilly day (maybe 48°). I love the brown hairs on his thorax. What is he?
How you want your letter signed:  gardenjim

Hover Fly:  Brachypalpus alopex

Dear Gardenjim,
Though the wings on your individual are smokier than we are used to seeing on a Drone Fly, we believe that is a correct identification for your fly.  The wing veination pattern on your individual matches that of this Drone Fly pictured on BugGuide as well as that of this Drone Fly pictured on BugGuide.  The Drone Fly is an Old World species that has naturalized in North America and it ranges from coast to coast.  The larva of a Drone Fly is known as a Rat Tailed Maggot.

Update:  Cesar Crash of Insetologia provided a comment and correction.  This appears to be a species of Hover Fly in the genus Brachypalpus from the same subfamily as the Drone Fly and there is an undescribed species posted to BugGuide from the same region as this sighting.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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