Millipedes vs. Centipedes

It’s not uncommon to confuse millipedes and centipedes since they share a few similar characteristics. But you may be surprised at how different these pests actually are from each other. Find out more about millipedes versus centipedes, including where you typically find them, if they cause any health concerns, and how to get rid of them.

What Are Millipedes? 

Millipedes have a simple life cycle that includes four stages: egg, hatchling, juvenile, and adult. Female millipedes lay their eggs in clusters in the soil or leaf litter, and their eggs are usually small, round, and white. After hatching, the millipede will begin to eat and grow quickly, molting several times. Once it reaches the juvenile stage, it will continue to eat and grow, molting several more times before reaching adulthood. Adult millipedes will have a full complement of segments, spending much of their time reproducing and eating. 

Millipedes can range from a few millimeters to about 4 inches. They have many more legs than centipedes and appear longer because millipedes have two pairs per segment. In general, common species of millipedes have between 34 and 400 legs since each segment of their body has multiple pairs of legs. A millipede has shorter, stronger legs than centipedes, allowing it to burrow and crawl more easily.

What Are Centipedes?

The lifecycle of a centipede begins with the female laying several dozen eggs in clusters. After hatching from the egg, the centipede has only a few segments but begins to eat and grow quickly. Once it reaches the juvenile stage, the centipede will have more segments and will resemble the adult in appearance. In the adult stage, the centipede stops growing and molting, having a full complement of segments.

Centipedes are larger than millipedes and can grow up to around 8 inches long. Some giant centipedes can reach lengths of up to 12 inches. Centipedes have fewer legs; they range from 15 to 177 per body segment, depending on the species. Their legs are slender and longer than millipedes and are adapted for quick movements, enabling them to escape predators or capture prey quickly. A centipede’s legs are also modified for grabbing and catching prey.

They can use some of their body parts to hunt for food. Their antennae are longer than those of millipedes, helping to find prey. Once they’re in contact with prey, centipedes use their front legs to kill it. Centipedes are carnivorous, eating other arthropods and worms, but their diet can vary. Some centipedes will also consume soft-bodied invertebrates and other arthropods.

Are There Different Types of Millipedes and Centipedes? 

Millipedes and centipedes are two kinds of arthropods that exist in thousands of different species. Being arthropods, millipedes and centipedes are closer to lobsters and shrimp than they are to insects. They both have segmented bodies and no direct reproductive organs. 

Millipedes. Millipedes are listed in the class Diplopoda, characterized by having many segments, each of which has two pairs of legs. They are usually slow-moving, are decomposers, and are often not harmful to humans.

Regardless of their sizes, colors, or shapes, millipedes have two pairs of legs per body segment. Some common millipede species include:

• Polydesmus angustus (The common millipede) 
• Anadenobolus monilicornis (The flower millipede)
• Narceus americanus (The giant millipede) 

Polydesmus angustus is found in Europe, has a long and narrow body shape, and grows to around 3-4 cm long. Anadenobolus monilicornis is found in the southeastern U.S., has a wide, flattened body shape, and typically grows to around 4-5 cm long. Narceus americanus is found in Eastern U.S. and Canada. This species has a wide, flattened body shape and short, thick legs, typically growing to around 7-8 cm long. 

Centipedes. Centipedes belong to the class Chilopoda, and they are found in many habitats around the world.

Some well-known centipede species include:

• Scutigera coleoptrata (The house centipede)
• Scolopendra heroes (The giant desert centipede)
• Lithobius forficatus (The stone centipede)

Generally, centipedes are gray, around 1.5 inches long, and have long and slender legs. However, these pests can vary significantly in size, shape, and color. Scutigera coleoptrata is likely the type that you see in your house. They’re found worldwide, are fast-moving, and can reach up to 15 cm long. Scolopendra heroes is a tropical centipede, reaching up to 20cm long with a venomous bite. 

Lithobius forficatus is found in Europe and North Africa, typically growing to around 8-10 cm long. This centipede is known for its strong jaws, venomous bite, and ability to regrow lost legs. 

All of these centipede species are predators. Depending on the species, they’ll typically feed on insects, spiders, and other small arthropods.

Where Do Millipedes and Centipedes Live? 

Millipedes and centipedes are often found in damp and dark environments, such as leaf litter, soil, logs, and under rocks. However, when it comes to their preferred habitat, there are some differences between the two. 

Millipedes often require a high-moisture climate to survive and can be found in various habitats where you’d typically find a lot of rain. However, as long as there’s the right amount of moisture, you could find them in other habitats, such as deserts, mountains, forests, caves, and even in your own home: basements, sheds, garages, under stones, and even in bathrooms.

Centipedes can survive in damp, dark environments, but they prefer drier habitats than millipedes. You can find these pests in areas with a wide range of temperatures. They are often active hunters and need open areas to move and catch prey.

Are There Health Risks From Millipedes and Centipedes?

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. On the other hand, centipedes are capable of biting and stinging if threatened. While the poison from a centipede bite is not typically deadly to humans, it can cause pain, swelling, and redness at the bite site, along with other symptoms such as fever, chills, and nausea.  

How Do You Treat Millipede and Centipede Exposure?

You may not consider skin-direct exposure to millipedes and centipedes as a common occurrence like spider bites or bee stings. Still, take the necessary steps to treat direct contact or bites to avoid infections.  

Millipedes. Millipedes can discharge substances causing irritation to your skin. Applying ice to the infected area typically helps to resolve irritation, and washing with soap and water should clear away the secretions. 

You can also use an over-the-counter corticosteroid cream to treat rashes. But, be careful not to touch your eyes during this time, as to avoid eye injury. If you get millipede secretions in your eyes, wash them out with water immediately and seek professional medical care. 

Centipedes. Wash the bite area with soap and water as soon as possible to avoid infection. Consider seeking professional medical care after centipede bites, as you may need a tetanus shot.

How Do You Get Rid of Millipedes and Centipedes? 

Both centipedes and millipedes are unwelcomed guests in your home, and there are a few do-it-yourself methods to getting rid of each.

To get rid of millipedes: 

• Reduce moisture levels in areas where you find them by fixing leaks, improving drainage, and increasing ventilation. Consider doing this in particularly damp areas, such as basements and crawl spaces. 
• Remove food sources, such as piles of leaves and other organic debris. 
• Seal cracks and gaps in the foundation, especially around doors and windows to prevent millipedes from entering your home.

To get rid of centipedes: 

• Reduce their food source, which includes other arthropods, spiders, and insects, by implementing integrated pest management methods, like reducing clutter, vacuuming and cleaning regularly, and applying pesticides if necessary. 
• Seal cracks and crevices around foundations, windows, and doors. 
• Replace or repair any damaged weather stripping, screens, or sealants to prevent centipedes from getting into your home.

If you have an ongoing problem getting rid of either, you may want to contact a professional exterminator to take over. Research reputable companies and ask about their extermination methods. Some companies use pesticides, while others use natural methods, such as pheromone traps or beneficial nematodes.

Always follow the safety instructions provided by the professional exterminator. Pesticides can be dangerous if not handled correctly. Keep children and pets away from the treated areas until the pesticide has dried. 

Note that professional extermination can only get rid of existing millipedes and centipedes. To prevent new pests from coming in, take the necessary steps to reduce moisture and seal entry points, helping to prevent future infestations.