Are millipedes dangerous? Frequently asked questions answered

John Henrique Oct 2, 2020

Are they poisonous? Where do they live? What do they eat? Do they bite? Are they different from centipedes? Find out more about this strange animal.

The millipede is a small animal that has many legs and a cylindrical, elongated shape.

It is a relative of the centipede and can be found all around the world.

There are between 8 and 12 thousand species of millipede worldwide. This animal likes wet and dark environments and usually feeds on organic materials and plants.

How many legs do millipedes have?

Although their name means “thousand-feet”, millipedes have, on average, 400 legs.

However, millipedes of the species Illacme plenipes, found in the United States, can have up to 750 legs.

A female Illacme plenipes (an inch-long millipede from California) with 618 legs.
A female Illacme plenipes (an inch-long millipede from California) with 618 legs. CC BY 3.0

How big are millipedes?

Most millipedes measure a few centimeters in length, usually around 3 centimeters (1.1 inches). But there is a species that deviates from the standard.

Archispirostreptus gigas, also known as the giant African millipede, can reach an astonishing 38.5 centimeters (15.2 inches) in length! No millipede is as long as this one.

Giant African millipede, Namibia.
Giant African millipede, Namibia. (Credit: Olga Ernst).

Millipedes scientific classification

Millipedes are Diplopoda – which means that they have two pairs of legs on each segment of their body (from Greek diploos ‘double’ + pous, pod- ‘foot’).

Diplopoda belong to the phylum of arthropods, which are invertebrate animals (they have no spine) and have an external skeleton (exoskeleton).

Now, let’s take a closer look at some frequently asked questions about millipedes.

Do millipedes bite? Are they dangerous? Are they poisonous?

Millipedes don’t bite and don’t sting. On the contrary: if you touch it, it will try to defend itself by curling up like a snake. This curling tactic protects the fragile parts of its body with its robust exoskeleton.

They are not venomous or poisonous, but they can release a toxin from their repugnatorial glands as a defense mechanism. This secretion, although toxic, is practically harmless to humans, and serves to ward off predators.

Millipedes curl up as a defense strategy.

In case of contact with the toxin, the symptoms range from nothing to itching and a burning sensation on the skin. In the eyes, it can cause redness and swelling.

According to the Merck Manual of Diagnosis and Therapy, the best thing to do in case of irritated skin by millipede secretion is to wash the affected area with soap and water.

If there is a skin reaction, it is recommended to use a product with corticosteroids. In the case of itchy eyes, wash them with water.

What is the difference between millipedes and centipedes?

Millipedes and centipedes are closely related evolutionarily. Both belong to the subphylum of the myriapods, but different classes.

The centipede belongs to the Chilopoda class. Unlike millipedes, centipedes bite and are venomous. So, it is important not to mistake one for the other.

Millipedes have a cylindrical, elongated body. Centipedes are usually brown, have a flattened body, and a pair of long antennae on their heads.

Additionally, unlike millipedes, centipedes do not have two pairs of legs in each segment of their body, a characteristic that defines the Diplopoda class.

Centipedes are agile and predatory animals. Their bite is painful, causes swelling and redness, and can even cause malaise and dizziness. Death by centipede bite is very rare.

Where do millipedes live?

Millipede on a decaying tree trunk.
Millipede on a decaying tree trunk. (Credit: depositphotos).

Millipedes live in cool, wet, low-light places.

They can be found in gardens, fallen tree trunks, pieces of wood, between stones, and inside containers.

They usually live in places that have some type of organic matter decomposing, like vegetable scraps.

They appear indoors on hot and rainy days, when humidity is high, mainly due to excess water in the gardens.

Millipede feeding on vegetable scraps.
Millipede feeding on vegetable scraps. (Credit: depositphotos).

Are millipedes important for the ecosystem?

Because they feed on decaying organic matter, millipedes are very important for the environment.

They return the minerals to nature, which will then be absorbed by plant roots. Millipedes are natural producers of organic fertilizer.

They assist in the process of transforming dead matter into nutrients, and by moving through the compounds, they promote oxygenation.

Are millipedes bad for plants?

They love to eat plants.

It is common to find them in the yard and sometimes even indoors. However, these animals pose no risk to you and your family.

The only drawback is if the millipedes decide to eat the plants in your garden. Yes, they are also parasites.

In addition to feeding on decomposing materials, they love to eat plants. So yes, they can be bad for the plants in your garden.

How to prevent millipedes from entering your home?

To prevent them from getting indoors, there are at least two basic recommendations:

  • Keep the house always clean, free of organic matter, such as food scraps.
  • Keep the house well ventilated and well lit. Remember: millipedes love wet and dark places.

How to deal with millipedes in the garden?

  • Keep the garden clean, not soaked;
  • Water your garden preferably in the morning. Millipedes are usually more active during the night. Ideally, the garden should have the opportunity to dry before these animals start their activities;
  • Remove all the leaves scattered around the yard and the remains of vegetables, as these animals feed on decomposing matter;
  • All trees must be pruned during the spring, so that air can circulate between them;
  • Check if the gutters are properly cleaned, free of leaves and debris;
  • If the above measures do not work, contact a professional to perform on-site pest control.

Related topics:

Centipedes Millipedes

Written by John Henrique

John has a degree in IT and is the founder of Hyperaxion. He is a science enthusiast and can usually be found reading a book, stargazing, or playing video games.


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