Millipede

Quick Take

• Millipedes are named for having 1,000 legs, though no millipede has ever actually had that many. The reality is even stranger. Check the real leg counts →
• Centipedes and millipedes look almost identical, but one of them will eat a whole frog while the other won't even bite you. See how they differ →
• The millipede may have been the very first animal to walk on land, and one ancient relative reached a size that would shock most people. Explore their ancient origins →
• Some millipede species produce a chemical defense potent enough to deter predators, yet their main survival strategy is something far more passive. Discover their chemical defenses →

The millipede belongs to the phylum Arthropoda, falling under the subphylum Myriapoda — distinct from spiders, which belong to subphylum Chelicerata, and butterflies, which belong to subphylum Hexapoda. They aren’t considered insects, though they have a hard exoskeleton that protects their bodies.

Though some species of millipede are poisonous, they are largely without defense against natural predators. They have no pincers, stingers, or claws to deter the animals that hunt them, and they don’t even bite. At most, they’ll release a toxin that creates an effect similar to an allergic reaction.

Centipede vs. Millipede

Though the millipede and the centipede are easy to confuse, there are a few major differences between them, starting with their classification.

While both the centipede and the millipede are arthropods, only the millipede belongs to the Diplopoda class. The centipede, on the other hand, belongs to the Chilopoda class.

The way legs are arranged along the body also differs: millipedes have two pairs of legs per body segment, while centipedes have only one pair. Additionally, the antennae make them easy to differentiate, since millipedes have short antennae and centipedes have long ones.

Millipedes prefer the vegetation they find underground, while some centipedes are so ravenous that they’ve been known to consume whole frogs. While centipedes bite, millipedes do not.

5 Incredible Millipede Facts

• Despite their name, millipedes don’t always have anywhere close to 1,000 feet. Most common species have between 34 and 400 legs, with most species having fewer than a hundred, though at least one record-setting species has been documented with as many as 1,306 legs.
• Archaeological findings suggest that the millipede was the first animal to walk on land, dating the species back to 400 million years ago. One ancient relative of millipedes, Arthropleura, grew to over 8 feet in length.
• As the millipede grows, it molts. When they are still young, these molting sessions allow them to grow additional legs each time.
• Potentially 80,000 species of these animals are alive in the world today, even though only 12,000 have been identified.
• The millipede’s heart runs the length of its entire body, and the aorta is located at the head.

Evolution and Origins

Millipedes are ancient arthropods that have existed on Earth for over 400 million years, long before the dinosaurs. They belong to the class Diplopoda and are known for their long, cylindrical body segmented by multiple legs.

Despite their name, millipedes do not have a thousand legs, with the number of legs varying from species to species, but usually, they have between 34 and 400 legs. Over time, millipedes have evolved to adapt to their environment.

Millipedes belong to a group of ancient arthropods known as the myriapods, which also includes centipedes and other multi-legged creatures, with the group’s origins tracing back to the Cambrian Period about 541 million years ago.

These ancient myriapods likely lived in the soil, where they fed on decaying vegetation and dead insects. As they evolved, millipedes developed a thicker and tougher exoskeleton to protect themselves from predators, and their legs grew in number to help them burrow deeper into the soil and avoid danger.

Over time, millipedes continued to evolve, adapting to different environments and ecological niches. Some millipedes developed the ability to produce defensive chemicals, such as hydrogen cyanide, to deter predators, while others evolved a more symbiotic relationship with plants, acting as pollinators and seed dispersers.

Species, Types, and Scientific Name

These animals are part of the Animalia kingdom classification, falling under the Arthropoda phylum. They don’t quite meet the standards for insect classification, due to the segmentation of their body.

They are much more closely related to spiders, though the millipede’s class is Diplopoda. ‘Diplopoda’ comes from the Greek words ‘diplous’ and ‘podos,’ which literally translate to ‘double foot’. This name likely refers to the two pairs of legs found on each body segment.

Even though the word “millipede” comes from a prefix that suggests that they have 1,000 legs, no recorded millipede has ever had this many.

In total, scientists have discovered approximately 12,000 different species, classified into 16 orders and around 140 families, spanning 2 subclasses:

• Penicillata (Bristle Millipedes), which has a soft body with bristles along its sides (1 order, Polyxenida).
• Chilognatha (Typical Millipedes), which is divided into two infraclasses (Pentazonia and Helminthomorpha) that include short-bodied millipedes and millipedes that look fairly similar to the worm.

Scientists believe that there are as many as 80,000 species of these animals in the world today.

Appearance

Much like other arthropods, millipedes have an exoskeleton, though at least one extinct species had a soft exterior. Ranging from as small as 0.08 inches (2 mm) to as large as 13.8 inches (35 cm), they are typically brown or black, with bright colors indicating that certain species are poisonous.

Certain species of millipedes can also grow quite large. For example, the African giant black millipede is the largest in the world and can reach up to 15 inches in length! Millipedes also have only a single pair of antennae, whose use is unknown.

The legs are an easy way to identify what kind of animal you are looking at. These animals have an average of 100 legs, but there are some giant variations that can have upwards of 750 legs. The legs are jointed, and each section of the animal’s exoskeleton has two pairs.

Habitat

Considering how many different species there are, they are found on nearly every continent. They prefer to burrow in their natural habitat, which often consists of warm and moist soil.

Millipedes rarely survive in the house. However, sometimes, garden millipedes become house millipedes after infiltrating the home, especially in extreme weather conditions. Regardless, they cannot survive indoors for long.

A millipede’s environment must be humid, even if kept as a pet in an artificial habitat. The only area that has yet to become the habitat of the millipede is Antarctica.

Diet

This animal is a detritivore, which means that it eats dead organic matter in the earth, like damp wood pieces, decayed leaves, and other materials that naturally exist in their moist habitat underground.

However, these opportunistic feeders won’t allow themselves to go hungry. If the land becomes overly dry or they are unable to consume the detritus that they normally eat, they’ll go after living plant life to satisfy their appetite.

Prevention

These animals are rather easy to eliminate from the home with either defensive insect sprays or simply picking them up to remove them from the home. They are not dangerous to humans, but they can be quite a pest in a healthy garden.