worm facts

14 Worm Facts That Will Surprise You

Worms are often rejected by many due to their unsightly appearance. Some are incredibly fearful of these weird-looking creatures. Individuals with scoleciphobia experience a severe phobia or intense fear of worms, resulting in nausea, increased heart rate, and trembling.

Despite the dislike of the majority, worms are interesting animals. An interesting worm fact is that they are cold-blooded and have five hearts. They can't live in dry and icy places. And they are also hermaphroditic, which means a single individual is of two sexes.

Worms live up to 8 years. They can regenerate, and new individuals can grow from a single fragment. Learn more about these exciting worm facts by reading on.

Related: Worms are also suitable for gardening. Here are some gardening quotes and some tips on what worms eat if you're keeping them in the garden or for vermicomposting.

Fun Facts About Worms

worm on ground
Photo by HelgaKa on Pixabay

1. There are three main groups of worms.

Worms are invertebrates with bilateral symmetry. They represent three main groups and phyla: flatworms (phylum Platyhelminthes), roundworms (phylum Nematoda), and segmented worms (phylum Annelida).

Segmented worms are well-adapted to life in soil environments. Their cylindrical bodies are segmented, allowing flexibility and efficient movement through the Earth. Earthworms are part of this group and play a vital role in soil health, burrowing through the ground and ingesting soil, extracting nutrients, and leaving behind nutrient-rich castings.

In contrast, flatworms possess a flattened body shape and lack segments. They can live in various habitats, including freshwater, marine, and terrestrial environments. Some flatworms are free-living, while others are parasitic.

Lastly, roundworms are unsegmented worms with long cylindrical bodies. They inhabit diverse habitats, including soil, freshwater, and marine ecosystems. Roundworms can survive in extreme environments and thrive in almost every ecosystem on Earth. Some examples of roundworms are Ascaris, parasites that can infest humans.

2. They can regrow body parts.

earthworm on road
Photo by _sandrakula_ on Pixabay

Planarians are flatworms known for regenerating lost segments. Individuals can regrow from a lost tail or limbs and even their entire heads, including the brain, due to a particular group of adult stem cells called neoblasts. 

Neoblasts are remarkable cells that can change into different specialized cells. When the body gets injured, these neoblasts go to the injured area and begin a complex tissue repair and growth process.

3. The largest worm is longer than an average man.

Australia is not just known for its koalas and kangaroos. In a part of Australia called Gippsland lives an incredible creature called the giant Gippsland earthworm. This species is the largest earthworm in the world, reaching an average length of 9 feet, longer than an average man!

The giant Gippsland earthworm lives near rivers and forests. These habitats provide nutrient-rich soil and are abundant in food. Sadly, the giant Gippsland earthworm population is in danger because of habitat fragmentation and pollution.

4. They improve soil quality.

earthworm on soil
Photo by Natfot on Pixabay

Perhaps one of the more well-known and interesting worm facts is that earthworms help keep the soil healthy and improve its quality. They help break down waste, making the ecosystem more sustainable. As they move through the ground, they create tunnels that allow air and water to reach deeper layers4.

Worm tunneling brings essential nutrient minerals like nitrogen, phosphorus, and potassium to the surface, making the ground fertile.

Furthermore, as worms tunnel deeply into the soil, they aid in the surface mixing of subsoil and topsoil3. The renowned scientist Charles Darwin even recognized their ecological importance and suggested that worms are the most important creatures on Earth.

Related: How to start a worm farm.

5. Worms are big eaters.

worm on wet ground
Photo by makamuki0 on Pixabay

Did you know you can find a million earthworms in one acre? They are not only abundant, but they are also heavy eaters. The common earthworm, Lumbricus terrestris, eats organic matter and decaying materials like leaves. Furthermore, they can eat up to a third of their body weight.

Earthworms have a body part called the gizzard that grinds up their food. As the food moves through their body, they absorb the necessary nutrients. The processed organic material or worm poop comes out as worm castings and acts as a natural fertilizer.

6. Their strong muscles and mucus help them move.

Have you wondered how worms move? Worms can move through the ground without legs because of the strong muscles that help them navigate their underground habitat. The earthworm, for example, has circular muscles that wrap around their bodies and longitudinal muscles that stretch along their length.

They can push through the ground by coordinating and stretching these long muscles1. Furthermore, their strong muscles help them push twice more than their body weight.

Another critical factor in their movement is the mucus they produce. Like the snail's mucus, this slime lubricates the surface of their bodies and reduces friction with the ground. Their sticky slime helps hold clusters of soil particles together in aggregates.

Furthermore, these segment worms also possess tiny hairs called setae. These hairs allow them to grip the surrounding soil particles while moving.

7. They have five hearts but no lungs.

Worms have an adaptation that sets them apart from many other creatures: they have five pairs of hearts. These major organs work harmoniously to pump blood throughout their bodies, ensuring efficient circulation. 

Additionally, worms have a fascinating way of obtaining oxygen. Earthworms breathe through their skin instead of relying on lungs or gills like other animals. This unique process, known as cutaneous respiration, allows oxygen to pass directly into their bodies while releasing carbon dioxide.

8. Earthworms are hermaphrodites.

worm on leaf
Photo by Eukalyptus on Pixabay

Many species, including the common earthworm, are hermaphrodites, meaning an individual has male and female sex organs6. However, they can't self-fertilize. This adaptation helps them grow their population quickly and increases their chances of survival.

The process of hermaphroditic reproduction in worms is quite intricate. They have a unique way of exchanging sperm. For example, earthworms align their bodies through a protective mucus layer during mating and sperm exchange.

Flatworms, conversely, have a unique and aggressive behavior called "penis fencing." These worms mate using their sharp penises to inject sperm into each other. After mating, worms create protective cocoons or egg cases to safeguard their fertilized eggs until they hatch.

9. Baby worms hatch from cocoons.

It takes two worms to mate. Once impregnated, they lay cocoons to protect their eggs. Like butterflies, these eggs develop inside the cocoons until they're ready to hatch. The number of eggs in a cocoon can vary from 1-20, depending on the species.

Once the eggs hatch, small, transparent baby worms emerge. These hatchlings waste no time and start eating organic matter while tunneling through the soil. For example, baby earthworms emerge from the cocoons fully developed.

As they grow, they continue the vital work of their species, ensuring that healthy soil supports their survival and the well-being of other creatures that rely on it.

worm crawling on asphalt
Photo by iGlobalWeb on Pixabay

Did you know that there's a competition that involves worms? Worm Charming is a unique competition that has become popular recently. It started in the UK in 1980 and has since spread to countries like the US and Australia. The objective of the competition is to lure as many worms to the surface as possible without hurting them or disturbing their homes.

Participants in Worm Charming use different techniques to attract the worms. The competitions have strict rules to ensure the safety of the worm, like not digging or using chemicals. After the event, participants usually return the worms to their natural habitat.

Worm charming is not just a fun spectacle; it also raises awareness about worms' vital role in our ecosystem. It reminds us to protect their delicate homes and appreciate their contribution to our planet.

11. Leeches are medically beneficial.

For many years, people have used leeches to help with health problems. These special worms can benefit people with blood clotting and swelling issues. 

The spit of leeches has a potent substance called hirudin, which prevents blood clotting. When applied to a specific body area, leeches help remove stagnant blood and improve blood flow. This substance can be beneficial in cases where blood is pooling due to venous congestion or compromised circulation2.

Furthermore, leech saliva contains analgesics and anti-inflammatory compounds. These substances can help alleviate pain, reduce swelling, and promote healing in certain conditions. Leech therapy has assisted in treating ailments such as arthritis, osteoarthritis, and musculoskeletal disorders, providing symptomatic relief to patients.

12. Earthworms die when overfed.

brown worm
Photo by anaterate on Pixabay

One of the most noteworthy worm facts is the protein poisoning phenomenon. This phenomenon, also known as "overfeeding syndrome," can occur in earthworms eating excessive protein-rich food.

Worms typically thrive on a balanced diet of organic matter, including a mix of proteins, carbohydrates, and other nutrients. However, when they receive overwhelming protein, it can lead to health issues. When the worm consumes excess protein, its digestive system may struggle to break it down efficiently.

This issue can result in the accumulation of undigested protein in their bodies, leading to imbalances in their internal environment. The excess protein can also create an acidic environment, disrupting the natural pH balance necessary for the well-being of the worm.

13. Worms don’t like bright lights. 

Certain species of roundworms exhibit an interesting behavior called phototaxis, which causes them to become paralyzed if exposed to light. This response might be a natural survival mechanism.

Worms may be eyeless, but they can sense light well through their nerves. When these worms encounter intense or bright light, it triggers a temporary paralysis of their muscles. This behavior helps them avoid potential threats or unfavorable environments. Once the worms leave the bright area, they regain their ability to move and function normally.

14. It's essential to protect worms.

earthworm on dirt
Photo by Leni on Pexels

Last, in our list of worm facts, we look at why we should protect these slithery creatures.

Since they work underground, people often overlook the terrestrial worms' role in the environment. However, these creatures turn dead vegetation and animals into nutrient-rich soil, promoting plant growth and supporting farmland. Worms also burrow and dig tunnels in the ground, which allows air and water to reach plant roots and other ground creatures5.

Sadly, worms face many challenges. Despite their wide distribution, they slowly lose their homes because of deforestation and cities taking over their habitats. Worms need food, oxygen, and a favorable temperature to survive.

Moreover, pollution from pesticides and fertilizers severely damages their food supply. Besides, climate change affects worm habitats and food availability. Protecting worms and their habitats is crucial to restoring the Earth's balance.

What is your favorite worm fact? Remember to share it with your friends!

Related: To further explore the animal kingdom, check out some of the other animals that start with W.

Pin Me:
Pin Image Portrait 14 Worm Facts That Will Surprise You

Quillin, K. J. (1998). Ontogenetic scaling of hydrostatic skeletons: geometric, static stress and dynamic stress scaling of the earthworm lumbricus terrestris. The Journal of Experimental Biology, 201(Pt 15), 2377-2393.


Whitaker, I. S., Oboumarzouk, O., Rozen, W. M., & Acosta, R. (2012). The efficacy of medicinal leeches in plastic and reconstructive surgery: a systematic review of 277 reported clinical cases. Microsurgery, 32(3), 240-250.


Blouin, M., Hodson, M. E., Delgado, E. A., Baker, G., Brussaard, L., Butt, K. R., ... & Brun, J. J. (2013). A review of earthworm impact on soil function and ecosystem services. European Journal of Soil Science, 64(2), 161-182.


Edwards, C. A., & Arancon, N. Q. (2022). The role of earthworms in organic matter and nutrient cycles. In Springer eBooks (pp. 233–274).


van Groenigen, J. W., Lubbers, I. M., Vos, H. M. J., Brown, G. G., De Deyn, G. B., & van Groenigen, K. J. (2014). Earthworms increase plant production: a meta-analysis. Scientific Reports, 4, 6365.


Michiels, N. K., & Newman, L. J. (1998). Sex and violence in hermaphrodites. Nature, 391(6665), 647.

Sign Up for Updates