19 Flat-Backed Millipede Facts You’ll Never Forget

Flat-Backed Millipede Fact File

Flat-backed millipedes are frequently mistaken for centipedes, and that is understandable, as they do appear alike, but there are numerous key differences that set centipedes and millipedes apart. For example, centipedes are commonly carnivorous in nature as they chase their prey, inject them with poison before eating them; millipedes, on the other hand, are detritivores which means that they feed on decaying plants consisting of leaf litter.

They are quite short in length in comparison to other species of millipedes. That is, they only have 20 segments which means they have a total of 40 legs.

If you like these then you should read our giant centipede facts and red millipede facts.

Flat-Backed Millipede

Fact File

What do they prey on?

Dead leaves, roots, fruits, decaying plant materials

What do they eat?


Average litter size?


How much do they weigh?


How long are they?

0.12-5.12 in (3-130 mm)

How tall are they?


What do they look like?

Yellow, ivory, orange, dark brown, reddish-brown, black

Skin Type

Wet slimy, exoskeleton

What are their main threats?

Habitat loss, predators, pesticides

What is their conservation status?

Least Concern

Where you'll find them

Grasslands, heathlands, moorlands, farmlands, woodlands, towns, forests, gardens


North Europe, southeastern United States





Scientific Name

Polydesmus angustus





Flat-Backed Millipede Interesting Facts

What type of animal is a flat-backed millipede?

There are various species of millipedes on this planet. One such species within this group is the flat-back millipede. Millipedes are very long segmented invertebrates. They are very slow creatures but are able to excrete an almond-smelling fluid, known as cyanide, from the sides of their body if threatened by predators like spiders.

What class of animal does the flat-backed millipede belong to?

Polydesmus angustus are millipedes that have many legs on the segments of their body, and they belong to the Diplopoda class of animals.

How many flat-backed millipedes are there in the world?

There is no exact estimate on how many Diplopoda millipedes there are in the world, but it is known that they are in abundance and are found all over the world, typically in the soil.

Where does a flat-backed millipede live?

The Polydesmus angustus millipedes are located on all continents besides Antarctica due to the fact that they are burrowers and need soil. They managed to find themselves spread across the world as they were transported by human beings when they translated soil. This species was discovered in northwestern Europe and by accident came into the southeastern United States. They have now been transferred to all parts of the world.

What is a flat-back millipede's habitat of choice?

Diplopoda millipedes generally find themselves living in dark, damp habitats. This species of millipedes are found beneath leaf litter, woodpiles, and stones. Soil dwellers are generally discovered within the top layer of the soil. They are mostly found in decaying leaf litter in the soil in the forest.

Who do flat-backed millipedes live with?

Like the yellow flat-backed millipede, millipedes and centipedes live a solitary life and only get together for mating during their breeding season.

How long does a flat-backed millipede live?

The exact lifespan of the giant flat-backed millipede is not certain, but it has been observed that these millipedes and centipedes may live up to 10 years in captivity with the proper habitat provided.

How do they reproduce?

Breeding season starts from late spring through the summer season and then once more in late summer through mid-fall. The male flat-backed millipedes only mate once. However, they do have the ability to mate more than once, though this is unlikely to happen. Males produce pheromones or chemical substances which can be appealing to females. They additionally make a squeaking sound to get females to mate with them. After mating, the females lay six or seven dozen eggs in spring and once more in summer. Each egg is deposited in a capsule. The young ones molt once within the egg and then hatch about a few months later. Cooler temperatures can delay the hatching up to numerous months. The flat-backed millipede larvae take numerous years to attain adulthood before they can start mating. Females may also produce a dozen batches of eggs throughout their long life.

What is their conservation status?

Millipedes and centipedes, of the order Polydesmida, are in abundance all around the world and have been categorized as of Least Concern by the IUCN.

Flat-Backed Millipede Fun Facts

What do flat-backed millipedes look like?

The young larvae have fewer amount of segments, which means as they grow more segments and more legs too.

Flat-backed millipedes are similar to centipedes. The bodies of the adult millipedes are flattened, dark brown, with approximately twenty body segments. The body segment that protects the back is ridged alongside its length. The antennae and legs of this specific species are typically longer than in most other species of millipedes. Another defense mechanism they employ when they feel threatened by a predator is to curl up into a ball. Centipedes only have one pair of legs on each of the segments, whereas millipedes have two pairs of legs on each of the segments.

How cute are they?

Millipedes and centipedes are not cute and instead are considered creepy as they have 40 legs and long antennae. However, this species of millipedes have fewer amount of legs compared to the other species of millipedes, and they are often found in leaf litter.

How do they communicate?

Unlike other insects, millipedes do not have good eyesight and rely on their antennae for direction, and it is believed that they communicate with each other using their scent or pheromones.

How big is a flat-backed millipede?

This species of millipede is 0.12-5.12 in (3-130 mm) in length. It is ten times bigger than the striped cucumber beetle.

How fast can a flat-backed millipede move?

There has been no research on how fast these millipedes move.

How much does a flat-backed millipede weigh?

There has not been any specific research on the weight of this millipede.

What is the name of the male and female of the species?

There are no sex-specific names for the males and females of this species.

What would you call a baby flat-backed millipede?

Baby flat-backed millipedes are known as larva.

What do they eat?

The diet of the flat-backed millipede includes dead leaves, roots, fruits, and decaying plant matter. They are often found in leaf litter in the soil searching for food.

Are they dangerous?

They are not dangerous to humans and may hide when confronted by them. Although when extremely threatened, their bite may cause irritation to humans.

Would they make a good pet?

No, these flat-back millipedes would not make good pets as they like to be in leaf litter and feed on decaying plants and therefore require this environment. They are also an important part of our cyclical ecosystem.

Did you know...

These millipedes have longer legs in length than other species of millipedes. They sometimes beat their legs on their body to attract a female to mate. The flat-backed millipede also likes to roll itself up when it is threatened to provide them with extra protection.

Can millipedes kill you?

No, millipedes cannot kill you. Are flat-backed millipedes poisonous? Yes, they do produce a poisonous fluid secretion that, at worst, will cause slight irritation of the skin, and it is recommended that it be washed off as soon as possible. Another interesting millipede is the giant African millipede.

Why are they called flat-backed millipedes?

They are known as flat-backed millipedes because they present on each other their body segments are wide keels which are called paranota. They are produced in the posterior half of each body ring behind the collum. Also, these millipedes are flat, hence the name!

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other insects from our water spider facts and imperial moths facts pages.

You can even occupy yourself at home by coloring in one of our free printable millipede coloring pages.



At Kidadl we pride ourselves on offering families original ideas to make the most of time spent together at home or out and about, wherever you are in the world. We strive to recommend the very best things that are suggested by our community and are things we would do ourselves - our aim is to be the trusted friend to parents.

We try our very best, but cannot guarantee perfection. We will always aim to give you accurate information at the date of publication - however, information does change, so it’s important you do your own research, double-check and make the decision that is right for your family.

Kidadl provides inspiration to entertain and educate your children. We recognise that not all activities and ideas are appropriate and suitable for all children and families or in all circumstances. Our recommended activities are based on age but these are a guide. We recommend that these ideas are used as inspiration, that ideas are undertaken with appropriate adult supervision, and that each adult uses their own discretion and knowledge of their children to consider the safety and suitability.

Kidadl cannot accept liability for the execution of these ideas, and parental supervision is advised at all times, as safety is paramount. Anyone using the information provided by Kidadl does so at their own risk and we can not accept liability if things go wrong.

Sponsorship & Advertising Policy

Kidadl is independent and to make our service free to you the reader we are supported by advertising.

We hope you love our recommendations for products and services! What we suggest is selected independently by the Kidadl team. If you purchase using the buy now button we may earn a small commission. This does not influence our choices. Please note: prices are correct and items are available at the time the article was published.

Kidadl has a number of affiliate partners that we work with including Amazon. Please note that Kidadl is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.

We also link to other websites, but are not responsible for their content.

Read our Sponsorship & Advertising Policy
Get The Kidadl Newsletter

1,000 of inspirational ideas direct to your inbox for things to do with your kids.

Thank you! Your newsletter will be with you soon.
Oops! Something went wrong while submitting the form.
No items found.
No items found.