Millipedes are small, slow-moving arthropods with no aggression, but when they gather in large numbers, they can be unnerving and not something people want around their home or business.
While many people first notice a single one curled up in the corner of a basement, millipedes can multiply quickly, and seeing dozens or even hundreds at once is a sure sign of a millipede infestation.
Millipedes are often confused with centipedes, but are quite different in structure and behavior. A centipede is a fast-moving predator that can bite, whereas a millipede is a decomposer that feeds on decaying organic material. These differences matter because they explain why millipedes are found in damp, dark places and why they may enter homes when their outdoor environment becomes too wet or dry. You can take the proper steps toward prevention by learning more about what millipedes are, how they live, and what draws them into homes and businesses.
Color: Dark brown to black, sometimes with red or orange markings
Legs: 30 to 400, depending on species and age
Shape: Long, cylindrical, and segmented body that curls into a spiral when disturbed
Size: 1/16″ to 4″ (2–100 mm)
Antennae: Short and slender, typically seven segments
Millipede identification is simple, they are like centipedes in many ways, just longer and less flat. Their bodies are cylindrical, worm-like, and they can measure anywhere between two and 160 millimeters in length. Each body segment typically has two pairs of legs, one of the key features distinguishing them from centipedes, which only have one pair per segment. A millipede is a member of the class Diplopoda. Although the name which translates to “thousand-leggers”, isn’t quite accurate. In reality, millipedes can have anywhere between 30 and 100 pairs of legs but not one thousand. They’re nocturnal scavengers, preferring to feed on decaying plants and dead insects when they can find them.
Millipedes move slowly, and when threatened, they curl into a spiral, protecting their softer underside and making themselves harder for predators to consume. This defensive posture is one of the first things people notice when they try to pick up or move a millipede. Though there are thousands of millipede species worldwide, most that appear in North America are less than four inches long.
Among the many species, those that most often become household nuisances thrive in moist environments. Some more frequently encountered include the common black millipede, the greenhouse millipede, and various flat-backed millipedes.
Each has its own appearance and habitat preference. For example, the common black millipede (Narceus americanus) can grow larger than other species, but the majority are relatively small and unassuming. All millipedes share similar behaviors, such as feeding on decaying material and seeking moisture.
While the exact species is less important to most homeowners, understanding that they are drawn to damp, organic-rich environments helps explain why they may suddenly appear in basements, bathrooms, or crawl spaces.
Millipedes behave very differently from centipedes, even though the two are often confused. Centipedes are predators that move quickly and defensive, while millipedes are slow, docile decomposers. They prefer to hide during the day and become more active at night, especially in humid conditions.
Millipedes do not bite, sting, or have venom. They do not have fangs, and they do not hunt prey. Instead, when they feel threatened, many species release a fluid from their bodies as a defense. This secretion can produce a mild irritation if it comes into contact with skin, sometimes leaving temporary redness or discoloration. The reaction is usually minor, but anyone who develops discomfort should wash the area thoroughly and consult a healthcare professional if symptoms persist. Pets are rarely affected, though it is always best to discourage them from provoking millipedes.
Millipedes also do not transmit disease. For this reason, they are classified as nuisance pests rather than actual threats. Still, their presence in large numbers can create stress for homeowners and may need help from a millipede exterminator.
The diet of a millipede centers on decaying plant material. They consume rotting leaves, organic debris, and fungi, helping break down matter and recycle nutrients into the soil. Because of this, millipedes are essential decomposers in the natural environment. They rarely feed on living plants; when they do, it is typically soft seedlings or roots in very damp soil. Inside homes, millipedes are not a threat to food or stored goods. Their presence indoors usually indicates that conditions outside were unfavorable, such as excessive rain or drought, and they wandered inside while seeking shelter.
The lifecycle of a millipede begins when eggs are deposited in moist soil. Once hatched, the larvae start with very few body segments and legs. Through molting, they shed their exoskeleton and grow, adding new segments and legs each time. This continues until they reach maturity. Most species live between one and two years, though some can survive longer in ideal conditions, with rare individuals living up to seven years. Because they reproduce in soil and thrive in moist habitats, populations can grow quickly around homes with heavy mulch, compost piles, or poorly drained foundations.
While one or two millipedes in your home may not cause concern, large numbers appearing at once indicate a potential millipede infestation.
If you have a millipede infestation, you'll probably notice them congregating around patios or sidewalks, especially after heavy rain. You may also find them in basements, bathrooms, and laundry rooms, particularly in properties with moisture problems. Their tendency to migrate indoors often occurs seasonally, when outdoor conditions become too wet or too dry.
Because millipedes are small and slow, they are rarely noticed until they appear in large volumes. This sudden appearance can be unsettling, and in some cases, people report seeing dozens or even hundreds gathering around light sources or trying to enter through cracks in doors and windows. Though they are not harmful, their sheer numbers can make them feel overwhelming, especially in commercial settings where customers may see them.
The best way to have millipede control in your home is by reducing the areas of moisture that draw them in.
First of all, they like moisture, so tackling any problem with damp areas inside is critical. You should ensure leaky pipes are repaired, gutters and downspouts drain properly, and irrigation systems are managed to avoid overwatering. Indoors, using dehumidifiers in basements and crawl spaces can help reduce humidity.
Landscaping choices also play a role. Thick layers of mulch, compost piles placed directly against foundations, or firewood stacked against walls create moist, shaded habitats that millipedes love. Moving organic material away from the house reduces the chances of millipedes gathering near entry points. Sealing cracks and gaps around doors, windows, and foundations further limits their ability to get inside.
While these methods may reduce millipede activity, it is important to understand that DIY prevention is often temporary. A professional solution will be needed for lasting results if there is a significant population outdoors. At Gregory Pest Solutions, we have comprehensive millipede solutions that target both the pests and the environment that supports them.
An expert exterminator from Gregory Pest Solutions will be your full-service pest solutions provider specializing in the effective removal and prevention of millipedes and their nests from your home or business.
When you hire us to evaluate how extensive your home’s pest problem is, one of our technicians will be sent to assess the situation and then formulate an environmentally friendly plan for removal and prevention. You can count on us for a professional pest-controlled environment.
Despite their name, millipedes never have a thousand legs. They usually have between 30 and 400 legs depending on the species and age.
Millipedes are not harmful to people or pets, though some can release a secretion that may irritate skin. They rarely damage plants, except for tender seedlings in very damp conditions.
Millipedes do not bite or sting. Instead, they may release a defensive fluid that can cause mild skin irritation, so it’s best to wash your hands if you handle them and contact a healthcare professional if irritation continues.
Millipedes help break down decaying plant material, turning it into nutrients that enrich the soil. They are an essential part of the natural recycling process.
Reducing moisture, sealing entry points, and keeping organic debris away from foundations can help limit millipede activity. For lasting results and peace of mind, professional millipede control from Gregory Pest Solutions is the most effective way to manage infestations.