Millipedes: What to Know

Medically Reviewed by Jabeen Begum, MD on January 11, 2024
6 min read

Many pests can make their way into your home. Most aren't dangerous, but some can pose a risk to your health and safety. One of these pests, the millipede, might be scary to see, but it's harmless to people.

If millipedes are in your house, you probably want to know how they got there, whether they're dangerous, and how to get rid of them. Here's what you need to know about these many-legged critters. 


Millipedes are members of the phylum, or group of animal species, called arthropoda. This group includes insects, but millipedes aren't insects. They're actually more closely related to other arthropods like shrimp, lobster, and crayfish. 

What do millipedes look like? 

Millipedes have a long, segmented, tube-shaped body. They range in size from less than an inch to more than 5 inches. Millipedes have many feet, and though they’re sometimes called thousand-leggers, they don't have quite that many. In fact, most species of millipedes have less than 100 feet. 

Millipedes vs. centipedes

Many people confuse millipedes and centipedes. They're closely related and look very similar. Both have long, segmented bodies, but millipedes are round and cylindrical, and centipedes have flatter bodies. Centipedes are also venomous (but not dangerous to humans), whereas millipedes are not. Another defining feature is their legs: Centipedes have two legs on each segment, and millipedes have four per  segment.

What do millipedes eat? 

Most millipedes are scavengers, and they like eating decayed things. They commonly feast on damp and decaying or rotting wood, manure, grass clippings, and decaying fruits. If they have no access to anything decaying to eat, they will eat plants, fungi, and normal fruits. Some millipedes are carnivores and prefer eating insects. 

What is the millipede's life cycle?

Millipedes can live up to 7 years. The millipede life cycle begins when a female millipede produces eggs, typically in soil. They can lay up to 300 eggs at a time. The eggs stay in the soil until they hatch a few weeks later. Millipedes molt, or shed their skin, up to 10 times before they reach adulthood. During this time, they grow bigger and add more segments and legs. They reach maturity in 2 to 5 years.

Types of millipedes

There are 7,000 species of millipedes. Some common types include:

  • The garden millipede is about 1 inch long and brownish-black in color. It's the most common type you'll see in your house.
  • The spirobolid millipede, also called the North American millipede, is common in gardens and forests. It's 4 inches long and has a black body with reddish rings.
  • The yellow-banded millipede is native to the Caribbean. It has a dark body with bands of yellow, and dark red legs. It can grow to 4 inches.

Millipedes live all over the world. Of the 7,000 species, 1,400 live in the United States and Canada. 

These wormlike creatures are found throughout the United States hiding under rocks, leaves, brick pathways, and other debris. They favor cool and moist locations and can't live for long periods in drier climates.

Why do you get millipedes? 

When it's very dry or hot outside, millipedes may come inside your house looking for a cool and moist environment. That's why you can often see them in your basement. If your home has a lot of dampness, then you're more likely to have millipedes. They also come inside when it's too wet outside and when it's very cold. If the foundation of your house isn't sealed very well, it's easier for them to find their way in. 


Many people wonder about the potential danger of millipedes. Do millipedes bite? Are millipedes poisonous? The answer to these questions is mostly no--millipedes are not usually dangerous, they don't bite, and they're not poisonous. In fact, they don't produce venom at all. Some people confuse millipedes with their cousin, the venom-producing centipede. But unlike centipedes, millipedes are pretty harmless and docile. 

Still, like most creatures, millipedes do have their own defense, which they use when they feel threatened. If a millipede is trapped and feels in danger, it can release chemicals to stop predators from coming near it, such as:

  • Hydrochloric acid
  • Hydrogen cyanide
  • Organic acids
  • Phenol
  • Cresols
  • Benzoquinones
  • Hydroquinones

Some of the fluid could be toxic in large quantities, but the amount millipedes produce is harmless to people.

Larger millipedes can spray fluids almost 3 feet. This could have effects on some people who are allergic. The fluid could burn your eyes, cause skin irritation in the form of itching, and even cause your skin to become discolored. Also, people who are allergic to millipedes may have an allergic reaction when touching them, which can show up as blisters, hives, or itching or burning. 

Are there health risks from millipedes?

Millipedes are not venomous, and you can consider most of them harmless. When threatened, they often curl up into a defensive posture but don't bite or sting. Only certain people who are allergic to them might have mild symptoms from touching one, or coming into contact with the spray from a large millipede. 

How do you treat millipede exposure?

If you have a reaction after touching a millipede, wash your skin with soap and warm water. You can also use an over-the-counter corticosteroid cream to treat rashes. Be careful not to touch your eyes to avoid irritation. If you get millipede secretions in your eyes, wash them out with water for 20 minutes, then get professional medical care right away.

If you have millipedes in your house, you'll see them. Look in dark, moist, cool areas where millipedes like to hide, such as your basement, garage, and crawl spaces. Since they like to eat decaying matter, you might spot them around firewood and compost piles. Check any possible points of entry, such as window wells and door gaps.


Millipedes who end up inside your home will likely only survive a few days. Treating the inside of your house with pesticides won't do much to prevent millipedes. It will kill the ones you have, but new ones will keep coming in.

You can make it less likely that millipedes will enter your home by controlling the outdoor environment to make sure it doesn't attract the creatures. 

  • Keep your yard clear of debris and decaying matter and mow and edge your lawn regularly. 
  • Rake up leaves, and move wood and compost piles away from your house. 
  • Don't put garden beds next to the structure, especially not near basements and crawl spaces. 
  • Weed prevention barriers can also attract millipedes. It's helpful to remove these if possible. 

Next, check the foundation of your home and your doors and windows. Seal up any cracks, door gaps, and holes in window screens. If you have dampness and humidity in your home, you can use a dehumidifier to dry out the air. Check pipes for leaks and air conditioners for condensation that could be dripping in your home. 

If these methods don't work, you have some other options:

Diatomaceous earth is an organic substance that can kill millipedes. You can put it around entry points like cracks, vents, doors, and windows.  

Pesticides can be used outside your house around the foundation. This will stop many of the millipedes from coming in but not all of them. Remember, pesticides are poisonous and should be handled carefully according to manufacturer instructions. It's best to call a professional pest control company to apply pesticides.   



You can prevent millipedes by keeping the area outside your home neat and free of decaying matter. Fix any leaks in your home and use a dehumidifier to dry out damp places.