Millipedes are slow-moving, worm-like animals with many body segments and many legs. Millipedes are often called “thousand leggers” because it sometimes appears as though they have a thousand legs – and one species does! The record number of legs found on a millipede (it’s from the Australian desert) is 1,306. Millipedes have two pairs of legs on each body segment, are slow moving, and should not be confused with centipedes (which only have one pair of legs on most body segments and are very fast runners). While centipedes have venomous jaws and eat small insects, millipedes mainly eat decaying vegetation and do not bite people or pets.
Most millipedes live in moist areas, like in the leaf litter on the forest floor, in decaying wood, under the bark of a dead tree, or in other vegetation. When exposed, they typically either curl up into a ball or release a chemical defense. This chemical defense usually has an odor and may stain your hands or fingers.
There are many different types of millipedes. Black and red species several inches in length are often seen and pose no danger or threat as a pest. These large millipedes, commonly known as cherry millipedes, should be left alone.
Sigmoria arcuata (one of a group commonly known as cherry millipedes) can grow up to 2 inches long. These millipedes are called cherry millipedes for the fruity odor then sometimes emit when disturbed.
Photo by Derek Hennen, Virginia Department of Conservation and Recreation
The millipede that most often invades homes in large numbers is the garden millipede. Garden millipedes are gray to brown and ½ to ¾ inch long. They are most active at night and mainly feed on dead plant material and occasionally young plants.
The garden millipede, Oxidus gracilis, can sometimes invade homes in large numbers.
Photo by Derek Hennen, Virginia Department of Conservation and Recreation.
Garden millipedes usually live outdoors in moist, protected areas such as under mulch and rocks. They can also live on trees, in tree holes, and even in clogged gutters. Unfortunately, these millipedes sometimes migrate in huge numbers, especially after heavy rains in the spring. During these mass migrations, they may enter homes. They climb walls easily and may enter through any small opening.
Millipedes do not carry serious diseases and do not damage food or belongings in the home, but their mere presence is often a nuisance. If crushed, millipedes can leave stains. Many millipedes have glands which produce fluids which are irritating and can cause allergic reactions. These fluids can be harmful to the eyes and produce a nauseating odor. It is important to wash hands thoroughly after touching a millipede.
Millipede Management
If garden millipedes are occurring in great numbers indoors, it is usually an indication that there is a large population in the area surrounding the home. To control these pests, the most important step is to remove materials that give them shelter in the immediate area around the home. This includes excessive mulch, leaf litter, thick grass, rocks, boards and similar materials.
De-thatching the lawn and mowing closely allows for drier conditions, which reduces the areas where they can live. Watering in the morning rather than the evening also gives the lawn a chance to dry before these creatures become active at night.
Try to prevent garden millipedes from entering the house by making sure doors and windows fit tightly and as many cracks and crevices are caulked as possible. Remember that they may be entering your home from high areas just as easily as low areas. In most situations, garden millipedes found indoors can be easily removed with a broom or vacuum.
Pesticides provide only temporary control unless the non-chemical measures are taken as described above. However, if necessary, pesticide dusts such as boric acid powder applied to cracks, crevices, and indoor void areas where millipedes enter homes will help eliminate them more quickly. Many pesticide powders will not work well if applied in areas that are too moist.
For millipedes found outside, pesticide sprays applied to foundation walls or other entry points can help reduce entry. When treating leaf litter or mulch, use enough water to penetrate the ground cover or rake the ground cover back before spraying to ensure that the pesticide reaches the areas where millipedes live. For pesticide applications both indoors and outdoors, make sure you only use products appropriately labeled for millipede control in the areas you are making your applications. However, remember that millipedes are part of the decomposer fauna that helps to recycle organic material, and they play an important role in nutrient cycling and soil health.
If garden millipede numbers are extremely high and difficult to control on your own, consider hiring a licensed pest control operator. Pest control professionals have special equipment and pesticide formulations that may be able to provide better control than common, non-professional equipment and materials. For tips on hiring a professional, see HGIC 2412, Choosing a Professional Pest Control Company. This free online resource provides more in-depth information on millipedes and centipedes that are present in the eastern U.S.
Originally published 05/99
