# Earthworm — Facts, Threats & Conservation

*Lumbricina*

> Earthworms are segmented worms that burrow through soil, eating organic matter and recycling nutrients as they go. They breathe through their moist skin, have no eyes or lungs, and are hermaphrodites.

**IUCN status:** Least Concern  ·  **WARN range:** Europe, Asia, North America, South America, Africa, Oceania

## Quick facts
| Fact | Value |
| --- | --- |
| Scientific name | Lumbricina (suborder) |
| Diet | Detritivore (decaying plant matter, soil organics) |
| Habitat | Moist soils worldwide |
| Lifespan | 1–6 years (varies by species) |
| Size | Commonly 5–30 cm (2–12 in) long |
| Top speed | Very slow; burrows through soil |
| Conservation status | Least Concern (IUCN, most species) |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Annelida
- **Class:** Clitellata
- **Order:** Opisthopora
- **Family:** Lumbricidae
- **Genus:** Lumbricus

## Conservation status
- **Status:** Least Concern (IUCN Red List category)
- **Population:** Global population not compiled for this guide
- **Trend:** See the IUCN Red List assessment
- **Assessed:** See the IUCN Red List assessment
- **CITES:** See CITES appendices
- Conservation figures are drawn from the IUCN Red List and CITES; this guide links to the authoritative sources rather than restating population counts.

## Key facts: Earthworm
- An earthworm's body is divided into many ring-like segments, most carrying tiny bristles called setae that grip the soil as it moves.
- As earthworms tunnel and feed, they swallow soil and organic matter and excrete nutrient-rich waste called castings.
- Earthworms are detritivores that feed on decaying leaves, roots, and other organic matter in the soil.

## Body and breathing
An earthworm's body is divided into many ring-like segments, most carrying tiny bristles called setae that grip the soil as it moves. It has no eyes, ears, or lungs, and breathes by absorbing oxygen directly through its moist skin. This is why earthworms must stay damp and often come to the surface after heavy rain.

## Soil engineers
As earthworms tunnel and feed, they swallow soil and organic matter and excrete nutrient-rich waste called castings. Their burrows loosen and aerate the ground, improve drainage, and mix decaying material deeper into the soil. These actions make earthworms vital for fertile soil and healthy plant growth.

## Diet and digestion
Earthworms are detritivores that feed on decaying leaves, roots, and other organic matter in the soil. Because they have no teeth, they swallow small stones and grit that grind food inside a muscular gizzard. Their digestion releases nutrients in a form plants can readily absorb.

## Reproduction and regeneration
Earthworms are hermaphrodites, with each worm carrying both male and female organs, but two worms still mate to exchange sperm. After mating, a band on the body called the clitellum forms a cocoon in which the eggs develop. Some species can regrow a lost tail end, though they cannot regenerate a whole new worm from any piece.

## What WARN does
WARN does not run a dedicated earthworm programme — this guide is part of the World Animal Rescue Network's free educational library. The earthworm is currently widespread and not globally threatened, and this guide helps readers understand the pressures that can change that. Building public understanding of species like the earthworm supports the broader conservation awareness that underpins WARN's partner-led rescue work across its network.

If clear, science-based wildlife guides like this help you understand and value animals, please consider supporting the World Animal Rescue Network's educational and rescue work so we can keep producing them.

## Frequently asked questions: Earthworm
### Do earthworms have eyes?
No. Earthworms have no eyes, ears, or lungs. They sense light and vibration through special cells in their skin and breathe by absorbing oxygen through their moist surface.

### Why are earthworms good for soil?
Earthworms loosen and aerate soil as they burrow, improve drainage, and produce nutrient-rich castings. This recycling of organic matter makes them essential for fertile soil and healthy plant growth.

### If you cut an earthworm in half, do both halves survive?
No, that is a myth. An earthworm cannot become two worms. The head end may survive and regrow part of its tail, but the tail end generally dies.

### What do earthworms eat?
Earthworms are detritivores that eat decaying leaves, roots, and other organic matter in the soil. They swallow grit that helps grind the food inside a muscular gizzard.

### Why do earthworms come out after rain?
Earthworms breathe through their skin and need moisture, but waterlogged soil can be low in oxygen. After heavy rain they often surface to breathe and move more easily across the wet ground.

### Where do earthworms live?
Earthworms live in moist soils worldwide, from gardens and farmland to forests and grasslands. They burrow through the ground, breathing through their moist skin rather than lungs, which is why they surface after heavy rain when waterlogged soil is low in oxygen. By aerating soil and excreting nutrient-rich castings, they are essential for fertile ground and healthy plant growth.

### Are earthworms dangerous?
Earthworms are not dangerous to people. They have no eyes, sting or venom and cannot bite. These segmented worms are detritivores that swallow decaying leaves, roots and other organic matter, using grit in a muscular gizzard to grind food. A typical earthworm is about 15 cm long and weighs around 5 g. They are hermaphrodites and play a vital role recycling nutrients in soil.

### How long do earthworms live?
Earthworm lifespan ranges from about one to six years depending on species and conditions, with six years cited as a typical maximum in this guide. They grow through ring-like body segments bearing tiny bristles called setae that grip the soil as they move. Because they breathe through moist skin, drought or dry soil is a greater threat than predators.

### How big is an earthworm?
Earthworms commonly measure 5–30 cm long, with a typical length around 15 cm and weight near 5 g. Their bodies are divided into many ring-like segments, most carrying tiny bristles called setae that grip the soil as they tunnel. Despite lacking eyes, ears or lungs, they sense light and vibration through their skin and are among the most important animals for aerating soil and producing fertile castings.

## Sources
- [Wikipedia — Earthworm](https://en.wikipedia.org/wiki/Earthworm)
- [Wikidata — Earthworm](https://www.wikidata.org/wiki/Q124378)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/earthworm