Last updated: May 27, 2024
Verified by: AZ Animals Staff
© iStock.com/Ozii45


Worm Scientific Classification

Haplotaxida and Lumbriculida

Read our Complete Guide to Classification of Animals.

Worm Conservation Status

Worm Facts

Dead animals
Name Of Young
Group Behavior
  • Herd
Fun Fact
Doesn’t have eyes.
Estimated Population Size
57 billion
Biggest Threat
Any predator
Most Distinctive Feature
Long cylindrical body
Other Name(s)
Gestation Period
2-4 weeks
Litter Size
Anywhere with moist soil
Small mammals, birds, amphibians, reptiles, other insects
Common Name

Worm Physical Characteristics

  • Brown
  • Grey
  • White
  • Pink
Skin Type
4-8 years
Varies by species
Varies by species
Varies by species
Age of Sexual Maturity
30-60 days

View all of the Worm images!

Share on:

Worms are one of the largest groups of invasive species in the world.


With over one million species, the bilateral symmetry of their elongated bodies makes them easy to identify. They can live on land and in the sea, moving along any surface with a slimy substance that comes from their skin. Worms are hermaphrodites, but they need a partner to reproduce.

Though the worm may seem harmless, many species have ways to hurt their predators with stinging or the release of poison.

5 Incredible Worm Facts!

  • Ringworm is a misleading phrase because it isn’t actually a species. Instead, ringworm is a type of fungal infection in the skin. Left untreated, ringworm can be quite painful.
  • A hammerhead worm eats other earthworms, and there is no known lifespan for it.
  • The Alaskan bull worm on Nickelodeon’s SpongeBob Square-Pants is not a real species. While a bull worm is real, the Alaskan bull worm on the show is based on a mythical creature. No worm as large as the Alaskan bull worm is depicted.
  • Earthworms exist as an invasive species around the world.
  • Worms do not have eyes. Instead, they have receptors that tell them if their surroundings are dark or light to indicate if they are underground.

Scientific Name

Macro shot of red worms Dendrobena in manure, earthworm live bait for fishing

Typically the word “worm” is used to refer to the



©Nick N A/Shutterstock.com

The scientific name of the worm is “Annelida,” belonging to 16 different families under the Clitellata class. Typically, the word “worm” is used to refer to the earthworm, but even that word includes millions of types of animals. With over 1 million species of worms that each have their own types of habitats, the 16 families that earthworms and other species typically fall under include:

  • Acanthodrilidae
  • Ailoscolidae
  • Alluroididae
  • Almidae
  • Criodrilidae
  • Eudrilidae
  • Exxidae
  • Glossoscolecidae
  • Hormogastridae
  • Lumbricidae
  • Lutodrilidae
  • Megascolecidae
  • Microchaetidae
  • Ocnerodrilidae
  • Octochaetidae
  • Sparganophilidae

The word “Annelida” comes from a modern Latin term in French – “annelés.” The Old French word “anel” means “a ring,” which comes from the Latin word anellus.

There are too many species to list, but here is just a small sample of the different types of worms:


Earthworm, Worm, Dirt, Garden, Mud

Most often, you’ll find earthworms with gray, pink, white, or reddish-brown skin to blend easily with the soil of their habitat.


Due to the millions of species around the world, you would think that the worm has quite a broad range of colors or physical differences, but it doesn’t. Generally, worms have no internal or external skeleton, moving around with the muscles of their tube-like body. They come in many shapes, though some resemble a flat cylinder or a leaf without any other appendages.

They are rather easy to identify. The earthworm covers many types of worms, but they generally lack bold coloration. Most often, you’ll find them with gray, pink, white, or reddish-brown skin to blend easily with the soil of their habitat. Some species of earthworms are so translucent that you can see their red blood through the skin.

To get around, the worm’s skin produces mucus which is why smooth and slimy to make movement easy. Their body is primarily made of a brain with a nerve cord attached internally with a skin-like texture externally. Many types of worms have no obvious defenses against predators, putting them rather low on the food chain. The hammerhead worm, however, is a flatworm with its own poison, notable by its wide head (much like a hammerhead shark).

Most of these animals are only a few inches long, though the longest species is called the bootlace worm. It stretches up to 180 feet long, and it is one of the longest animals in the entire world. However, it is not the largest. All worms have bilateral symmetry. Bilateral symmetry means that the right and left sides of the invertebrate are identical mirror images.


Fear of Animals: Helminthophobia/Scoleciphobia

In one acre of land, there can be more than a million earthworms.


Like cattle or even many species of fish, the earthworm generally is part of a larger group called a herd, according to scientific research. With touch, they are able to communicate and make decisions as part of a group. They’ll decide where they want to travel collectively, using taste and sense vibrations in the soil to send messages to each other.

Generally, worms tend to stay buried underground to hide from predators. Some species – like the jumping worm – will bite when disturbed. The jumping worm is known by many names, like the Georgia jumper, crazy worm, and snake worm. Most earthworms stay in the soil to avoid any interaction, but the jumping worm is quite violent if provoked.


Hammerhead Worm

Classrooms used to dissect hammerhead worms in Louisiana due to their abundance.

©zaidi razak/Shutterstock.com

Due to the worldwide distribution of worms, the main place to find the earthworm is in moist soil and areas with dead plant material. Most commonly, the earthworm is found in forests with a lot of rain, but their habitat varies. The only real necessity for any type of earthworm habitat is moist soil. As the invasive species that many worms are, they live on land and in the sea, which is part of the reason that they have so many predators. You can create a worm habitat at home within a tank or a garden.

Rather than migrating from one region of a continent to another, worms migrate deeper into the earth to avoid being struck by frostbite in the fall. To maintain moisture within the herd, as many as 100 worms will bond together until the cold season has passed. Some species will go as little as 5-10 meters to migrate, while others go much further.

Predators & Threats

What Do Robins Eat
Worms are threatened by nearly any species of predator that eats invertebrates as a typical part of their diet, including birds.

Much of the diet of a worm is comprised of things that they can find in the soil around them, like roots or leaves. They also consume the manure of other animals in the soil to provide them with the necessary nutrients to grow. Rather than maintaining an entirely herbivorous diet, many worm species also consume living organisms like fungi and bacteria. They’ll also consume decomposed animals, though the hammerhead worm is a distinct exception.

Worms are threatened by nearly any species of predator that eats invertebrates as a typical part of their diet. Some earthworms are a threat to other worm species, like the hammerhead worm. The hammerhead worm has no problem consuming other earthworms, maintaining a carnivorous diet, and is just as toxic as consuming an improperly cooked pufferfish.

Predators don’t need much effort to attack an earthworm. If the animal can dig enough to find an earthworm, as long as they don’t have their own poison, they are easy to consume. Some species are even prepared as a delicacy for humans.

At this point, no conservation efforts are necessary to maintain the population.

What Eats Worms?

Since the worm is an invertebrate, it is easily consumed by thousands (if not millions) of different types of animals. Some animals that eat worms include birds, bats, beetles, wasps, amphibians, salamanders, toads, skunks, and moles.
Worms are such a good source of enticing nutrients that they are even used by humans to catch fish and other animals.

What Do Worms Eat?

The majority of a worm’s diet consists of what they can find in the soil. They aren’t particular to any animal that has perished.

Reproduction, Babies, and Lifespan

earthworm in dirt in someones hands

When they are born, worms immediately burrow into the soil after hatching.


To mate, worms line up against each other on their sides, touching their tail to the head of the other worm. The males excrete sperm packets, and the females store the packets in their female pores. Gestation takes 2-4 weeks, laying up to 20 eggs in a cocoon. Worms are hermaphrodites, but they require a partner to reproduce.

Baby worms are called hatchlings. When they are born, they immediately burrow into the soil after hatching. They do not stay with the parent for any length of time.

The average lifespan of a worm is 4-8 years old. However, due to their status at the bottom of the food chain, very few worms live to old age.

Worm Population

Common Earthworm Nightcrawler (Lumbricus Terrestris)
The Earthworm Nightcrawler is just one of 1 million species of worms.

In the entire world, there are approximately 57 million worms, and the number continues to grow with over 1 million different species. Though some species can be particularly helpful in gardens and other areas with a lot of moist soil, they are invasive species. No conservation efforts are currently being made on behalf of worms.

Origin and Evolution

Earth worm isolated on a white background.

The origin of today’s earthworms is from the general area of Europe.

©Picture Partners/Shutterstock.com

Though worms might have existed millions of years ago, experts believe native worm species were wiped out when glaciers covered the earth. The origin of today’s earthworms is from the general area of Europe. They traveled in the rootstocks of plants that were taken on voyages.

In the 13th century, worms were actually recognized in Europe as part of the category of reptiles that consisted of a miscellany of egg-laying creatures, which were labeled by Vincent of Beauvais in his Mirror of Nature. These days, the outdated term worm is applied to various other living forms such as larvae, insects, centipedes, and even some vertebrates. 

View all 109 animals that start with W

Share on:
About the Author

Bethany is a professional copywriter and editor, working with newspapers, small businesses, Fortune 500 companies, and everything in-between. She graduated from Penn State University with degrees in journalism and international studies. She loves her cat, Maggie, and has had numerous pets over the years, including guinea pigs, hermit crabs, fish, and a red-eared slider turtle. She lives among farmlands in southcentral PA and enjoys gardening, cooking, reading, and sewing.

Worm FAQs (Frequently Asked Questions) 

What is a worm?

A worm includes any invertebrate animal that has a long body with no appendages. They cover over 1 million different types of invertebrates, and they are considered invasive species. They are divided into three groups, which include the flatworm, the roundworm, and the segmented worm. With bilateral symmetry, their body is perfectly proportioned on both sides.

Is a worm an animal or insect?

Worms are animals.

Is it safe to eat worms?

Yes, you can eat worms. However, there’s a chance that this animal can carry parasites, so it is best to cook them before eating. Maggots can grow and cause bacterial poisoning.

Can a worm hurt you?

Yes, some types of worms can cause infections, but the majority of these infections aren’t serious. Human-made medicine should be enough to handle it.

Can worms bite?

Some types of worms have some way of biting. Predominantly, the pain comes from a sting, rather than an actual bite.

How many species of worms are there?

Over one million species of worms exist naturally today.

Are worms carnivores, herbivores, or omnivores?

For the most part, worms maintain an herbivorous diet, allowing them to live in gardens and other habitats with a lot of plant life. However, they will also consume dead animals when the opportunity arises.

How many hearts does a worm have?

Worms have five hearts.

Are pinworms dangerous?

Pinworms are an intestinal infection. They are dangerous because they cause some symptoms.

What do wax worms eat?

Wax worms eat the pollen, beeswax, shed bee skins, and cocoons found in honeycomb.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.


  1. Fact Monster / Accessed December 21, 2021
  2. Sciencing / Accessed December 21, 2021
  3. Guinness World Records / Accessed December 21, 2021
  4. Earth News / Accessed December 21, 2021
  5. University of Michigan Medicine / Accessed December 21, 2021
  6. Thought Co / Accessed December 21, 2021
  7. Fandom / Accessed December 21, 2021
  8. Biokids / Accessed December 21, 2021
  9. Nacdnet / Accessed December 21, 2021
  10. Pets on Mom / Accessed December 21, 2021
  11. Woodland Trust / Accessed December 21, 2021