Content Updated: March 23, 2026

Despite the commonly believed (and widely circulated) belief, millipedes don’t actually have a thousand legs. Of the many thousand millipede species that exist worldwide, around 1,000 live in the United States and Canada alone. If you’ve noticed these long, many-legged creatures, you might be wondering are millipedes poisonous, just how big they can get, or how to tell a centipede vs millipede. Keep reading to learn the answers.

Key Takeaways:

  • Millipedes are harmless, slow-moving arthropods that feed on decaying plant material.

  • It's easy to mistake millipedes for centipedes, so knowing the difference helps put your mind at ease.

  • From cylindrical to flat-backed, different millipede species all play a crucial role in maintaining healthy soil.

  • If millipedes start invading your home, professional millipede control from Terminix can help remove them.

What is a millipede?

A millipede is a slow-moving, moisture-loving arthropod with a long, segmented body and two pairs of legs per segment, which can give them anywhere from a few dozen to a few hundred legs. They belong to the class Diplopoda, which includes many different kinds of millipedes you might commonly find outdoors or occasionally inside. While generally harmless, it's helpful to know more about millipedes and how Terminix can help manage unwanted indoor visitors.

Millipede Species

There are numerous types of millipedes, but homeowners mostly encounter two primary types. Spirobolid millipedes are round and cylindrical, while flat-backed millipedes are flatter with ridged edges that give them a more geometric look. Both millipede species help recycle decaying leaves and enrich soil, which is great for nature, but not so great for your hallway. If these different kinds of millipedes start showing up inside, millipede control can help send them back outdoors.

American giant millipede

The North American millipede is found throughout the United States and is commonly referred to as the American giant millipede due to its large size.

  • Scientific name: Narceus americanus

  • Size: 1–4"

  • Color: Brown to dark brown

  • Leg count: 60–400 legs

  • Dangerous? No, but can release a defensive odor

Giant African millipede

The giant African millipede is the largest of all millipedes and is found, as you may have guessed, in Africa.

  • Scientific name: Archispirostreptus gigas

  • Size: Up to 10"–12"

  • Color: Dark brown to black

  • Leg count: 200–400+ legs

  • Dangerous? No, but can release a defensive odor

Yellow-banded millipede

First spotted in the U.S. after making their debut in Florida, yellow-banded millipedes are now turning up in other warm, moist environments across the country.

  • Scientific name: Anadenobolus monilicornis

  • Size: 2–4"

  • Color: Black with bright yellow bands

  • Leg count: Around 200 legs

  • Dangerous? Not poisonous, but their secretion can irritate skin

Desert millipede

These millipedes are desert dwellers, mostly seen across the southwestern U.S. and northern Mexico.

  • Scientific name: Orthoporus ornatus

  • Size: 4–6"

  • Color: Tan, brown, or reddish

  • Leg count: 100–300 legs

  • Dangerous? No

Shocking pink dragon millipede

Found in Southeast Asia, the pink dragon millipede's bright color is a warning to predators that it produces a chemical defense.

  • Scientific name: Desmoxytes purpurosea

  • Size: 1–1.5"

  • Color: Hot pink

  • Leg count: About 100 legs

  • Dangerous? No, but may irritate skin if handled

Sierra luminous millipede

This tiny type of millipede glows in the dark, using bioluminescence to deter predators in the forests of California's Sierra Nevada.

  • Scientific name: Motyxia sequoiae

  • Size: Around 1"

  • Color: Brown with glowing green markings

  • Leg count: 80–100 legs

  • Dangerous? No

Greenhouse millipede

This small but widespread millipede species is commonly found in greenhouses and in plant soil around the world.

  • Scientific name: Oxidus gracilis

  • Size: 0.5–1"

  • Color: Dark brown with pale stripes

  • Leg count: 80–100 legs

  • Dangerous? No