Earthworm
Lumbricina
Quick answer
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. By aerating and mixing soil and producing nutrient-rich castings, they are among the most important animals for healthy ground and farming.
Earthworm facts at a glance
| 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) |
| Kingdom | Animalia |
|---|---|
| Phylum | Annelida |
| Class | Clitellata |
| Order | Opisthopora |
| Family | Lumbricidae |
| Genus | Lumbricus |
Where it lives
Moist soils across every continent except Antarctica, with many species spread worldwide.
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.
Frequently asked questions about the 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.
