Millipedes Pest Control and Treatment

Millipedes Pest Control

Millipedes are slow-moving arthropods known for their long, segmented bodies and numerous legs. Despite their name, they don’t actually have a thousand legs — most species have between 30 and 400. Unlike centipedes, which are fast predators, millipedes are primarily scavengers, feeding on decaying organic matter such as leaves, wood, and soil debris.

In Australia, millipedes are generally harmless to humans, but some species can become major household pests. The introduced Portuguese millipede (Ommatoiulus moreletii), in particular, is notorious for invading homes in huge numbers, especially during autumn and spring.

What Do Millipedes Look Like? 

Millipedes have long, cylindrical, worm-like bodies made up of many segments, each bearing two pairs of short legs. Their colouring varies depending on the species, from dark brown and black to reddish-brown. Adults range in size from just a few millimetres to more than 100 mm in length.

When threatened, millipedes curl into a tight spiral to protect themselves and may release a foul-smelling fluid that can stain surfaces or irritate sensitive skin.

Where Do Millipedes Live?

Millipedes thrive in damp, dark, and sheltered environments, such as under leaf litter, mulch, logs, rocks, and garden debris. They are particularly active after rain, when moist conditions allow them to move around more freely.

Outdoors, they play an important role in breaking down organic matter and enriching soil. However, when conditions become too wet or too dry, millipedes may migrate en masse, often invading houses, garages, and sheds in search of shelter. This behaviour makes them a nuisance pest, particularly in southern Australia where Portuguese millipede infestations are common.

Common Types of Millipedes in Australia

Australia is home to many native millipede species, most of which are harmless and play a role in recycling organic matter. However, one introduced species in particular — the Portuguese millipede — has become a widespread household pest. These millipedes are known for invading homes in large numbers, especially during damp weather or seasonal migrations.

Below are the main types of millipedes you are likely to encounter in Australia and why they may be a problem.

Portuguese Millipede (Ommatoiulus moreletii)

How they look
Portuguese millipedes are smooth, cylindrical, and dark brown to black in colour. They typically grow to about 20–45 mm in length and are distinguished by their tendency to curl into a tight spiral when disturbed.

Where they live
Native to Europe, Portuguese millipedes were accidentally introduced to Australia and have spread widely across South Australia, Victoria, Tasmania, and parts of Western Australia. They are especially active after rain and during autumn when they migrate in large numbers.

Why they are a problem
Unlike many native species, Portuguese millipedes are attracted to artificial light, which causes them to swarm into homes, garages, and even washing machines at night. When crushed, they release a foul-smelling yellowish fluid that can stain fabrics and irritate skin. While not dangerous, their sheer numbers make them a serious nuisance pest in affected areas.

Native Millipedes

How they look
Australia’s native millipedes vary widely in size and colour, often brown, reddish, or black. They typically have a rougher, more textured body compared to the smooth Portuguese millipede.

Where they live
Native millipedes are found across Australia, usually in bushland, gardens, and under decaying vegetation. They prefer damp, shaded areas where organic matter is abundant.

Why they are a problem
Native millipedes rarely enter homes in large numbers and are generally not considered pests. However, they can sometimes wander indoors during heavy rain or seasonal changes, where they become an annoyance rather than a threat.

How to Identify Millipede Infestations 

Seasonal Swarming

One of the clearest signs of a millipede infestation — particularly the invasive Portuguese millipede — is the sudden appearance of hundreds or even thousands of millipedes during their seasonal migrations. This usually happens in autumn and spring, especially after heavy rain. They may be seen crawling across driveways, patios, gardens, and even inside homes.

Indoor Activity

Unlike most native millipedes, Portuguese millipedes are attracted to artificial light, which causes them to crawl into homes at night. They are often found in bathrooms, laundries, kitchens, or congregating around light fittings and windows. Large numbers indoors are a telltale sign of infestation.

Garden and Outdoor Presence

In the garden, millipedes hide under rocks, logs, mulch, and leaf litter. While they generally feed on decaying plant matter, heavy infestations can spill over into gardens where they damage seedlings, fruits, and soft plants. Trails of multiple millipedes moving together, especially after rain, indicate a nearby infestation.

Defensive Secretions

When disturbed or crushed, millipedes release a yellow-brown fluid with a foul odour. This secretion can stain floors, carpets, or fabrics, and may cause mild skin irritation in sensitive individuals. Frequent sightings of these stains in entryways or near walls suggest a recurring infestation.

Signs of Heavy Infestation

In severe cases, large numbers of millipedes will invade buildings nightly, often entering through cracks, vents, or under doors. Infestations may overwhelm indoor spaces, with millipedes appearing in cupboards, bedding, or even washing machines.

Outdoors, lawns, patios, and driveways may be covered with migrating millipedes, making normal activities unpleasant. At this stage, professional pest control is often required.

How to Prevent Millipede Infestations

Millipedes, especially the invasive Portuguese millipede, can invade homes in large numbers during certain seasons. While they are mostly nuisance pests, their swarming behaviour and attraction to artificial light make prevention essential. By reducing the conditions that attract them and blocking their entry points, you can minimise the risk of infestation.

Reduce Outdoor Attractants

Millipedes thrive in damp, sheltered environments. Keep your yard tidy by removing piles of leaves, mulch, grass clippings, firewood, and compost near the house. Trim back ground-covering plants and maintain well-drained garden beds. Reducing moisture and shelter limits the spaces where millipedes can hide and breed.

Manage Lighting

Portuguese millipedes are drawn to artificial lights at night. Reduce outdoor lighting where possible, use yellow “bug-safe” bulbs, or switch off unnecessary lights in the evening. Closing blinds and curtains can also help reduce indoor light spill that attracts them.

Seal Cracks and Gaps

Inspect your home for entry points around doors, windows, vents, and foundations. Install weather stripping and door sweeps, seal cracks with caulk, and fit insect mesh to vents. Blocking these access points makes it harder for millipedes to enter.

Improve Drainage and Ventilation

Millipedes prefer damp conditions. Fix leaking taps, downpipes, or gutters, and improve subfloor ventilation. Ensure garden beds slope away from the home so water doesn’t pool near foundations.

Regular Cleaning

Sweep and vacuum regularly to remove millipedes that manage to get indoors. Prompt removal discourages chemical staining from their defensive secretions and prevents odours from building up.

Act Quickly During Swarms

If you notice millipedes beginning to gather around your property during their seasonal migrations, act fast. Remove them with brooms, vacuums, or traps before large numbers establish themselves indoors.

How to Get Rid of Millipede Infestations

Millipedes can become overwhelming when they invade homes and gardens in large numbers, particularly during wet weather or seasonal migrations. While they don’t bite, sting, or damage property, their sheer numbers and defensive secretions make them a nuisance pest. Effective control often requires a combination of at-home measures and professional pest treatments.

At-Home Actions to Get Rid Of Millipedes

Physically Remove Them
The simplest way to deal with millipedes indoors is to sweep or vacuum them up. Dispose of them in sealed bags or containers to prevent them from crawling back inside.

Reduce Moisture
Since millipedes thrive in damp areas, addressing moisture problems is key. Fix leaks, improve drainage, and reduce watering in garden beds near the house. Dry environments are far less attractive to them.

Seal Entry Points
Close gaps under doors, around windows, and in foundations with weather stripping, sealant, or door sweeps. Insect mesh can also be fitted to vents and weep holes to reduce access indoors.

Outdoor Barriers
Residual insecticide sprays can be applied around the external perimeter of the home, garden beds, and entry points. These treatments create a chemical barrier that reduces the number of millipedes crossing into your property. Always follow product instructions carefully, especially around children and pets.

Professional Millipede Treatments

While DIY measures can help, severe infestations—especially during seasonal swarms—often require professional intervention. Licensed pest controllers use targeted treatments that are more effective and longer-lasting than store-bought products.

Perimeter Sprays and Barriers
Technicians apply professional-grade residual sprays around the outside of buildings, creating a long-lasting protective zone that stops millipedes before they enter.

Subfloor and Garden Treatments
Specialist treatments may be applied to subfloor areas, retaining walls, garden beds, and lawns where millipedes breed and shelter. This reduces population numbers at the source.

Ongoing Monitoring
Because millipedes migrate seasonally, pest control services often include monitoring programs to check for new activity and reapply treatments as needed.

Call a Pest Control Professional

While millipedes aren’t dangerous, they can invade in overwhelming numbers, leaving behind mess and odour. Once they’ve established themselves indoors or in garden areas, DIY methods may only provide short-term relief.

A licensed pest control company can assess your property, identify entry points and breeding sites, and apply safe, effective treatments tailored to your situation. Preventative strategies can also be recommended to stop future infestations.

Need help now? Book a professional millipede inspection on 1300 766 614. Our experts will inspect your property, explain your treatment options, and create a customised plan to eliminate millipedes and keep them out.

Frequently Asked Questions (FAQ)

What do millipedes eat? 

Millipedes are detritivores, meaning they feed primarily on decaying organic matter such as rotting leaves, wood, and plant material. Occasionally, they may nibble on living plants, but they are far more interested in moist, decomposing material.

Are millipedes poisonous? 

Millipedes are not poisonous and they do not bite or sting. However, when threatened, they can release a defensive fluid that has a strong odour and may cause mild skin irritation or staining. It’s best to wash your hands after handling them.

Are millipedes dangerous? 

No, millipedes are generally harmless to humans and pets. Their main nuisance is invading homes in large numbers, especially after heavy rains or during seasonal migrations. The defensive fluid they secrete can be unpleasant but is not dangerous.

Where do millipedes live? 

Millipedes thrive in damp, dark environments. Outdoors, they are commonly found under mulch, leaf litter, stones, logs, and in garden beds. Indoors, they may seek shelter in basements, bathrooms, laundries, and other areas with high moisture.

How long do millipedes live?

Most millipede species live between 1 to 2 years, though some can survive up to 7 years under the right conditions. Their lifespan depends largely on moisture levels and access to organic material for food.