Common Name:  Pill Millipedes

Scientific Name:  Glomeris connexa

Kingdom: Animalia

Phylum: Arthrpoda

Class: Diptopoda

Order: Glomerida

Family: Glomerida

Genus: Glomeris

Species: G.  connexa


Did you know there is a bug that can roll itself into a ball? Yes, a ball! It’s called a pill millipede. This is a short, stout, blackish, grayish hard bug that lives in the Northern Hemisphere. Read along and found out how interesting this roly-poly bug is.


This creepy crawly bug has a shiny cuticle, a large shield-like plate behind its head. The female length is 7-15 mm and the male length is 8-20 mm. They are a shiny black/gray color. They are able to go into a complete ball tucking their head and legs into their body. They have 7 sets of walking legs.


Pill millipedes are mainly found in the United States, Canada, and Europe. It’s hard to determine the population because it varies on the weather and food source. The conservation has not targeted this common species. They prefer calcareous soils and can be found among leaf litter in woodlands.


They are usually nocturnal and may venture over considerable distances during the night. On humid evenings, they can often be seen in large numbers with the help of a flashlight.  They feed mostly on dead plant matter, although they have been known to feed on cultivated plants, such as ripening strawberries and tender seedlings. Pill millipedes then recycle the nutrients back into the soil. Pill millipedes form an important component of the larger decomposer fauna, along with earthworms, snails, and millipedes. All of these animals return organic matter to the soil where it is further digested by fungi and bacteria, hence making nitrates, phosphates, and other vital nutrients available to plants. Although they may occasionally feed on roots, pill millipedes do minimal damage to live vegetation and should not be regarded as pests. Their known predators are snails, slugs, and spiders. They defend themselves by rolling into a ball and when that does not work they use a chemical defense. Among their body are pores that release a smell that call kill or scare off other small creatures. This is toxic to another bugs but not humans. It’s like a toxic amore bug.


Pill millipedes are also of importance in sites such as coal spoils and slag heaps, which face heavy metal contamination. They are capable of taking in heavy metals such as copper, zinc, lead and cadmium and crystallize these out as spherical deposits in the midgut. In this way, they remove many of the toxic metal ions from the soil, promoting the restoration of contaminated sites by accelerating topsoil formation. This in turn favors the establishment of plants that stabilize the soils by root formation. Stabilized soils reduce problems of toxic dusts and the leaching of metal ions into the ground water. Who would have thought these little guys in their own little way are doing something for the bigger cause!


Author:   Aaron Cruz

Published: 02/2012



1) <a href="  HABITAT.html">Millipedes: Diplopoda - Habitat</a>

2) P.R. Racheboeuf, J.T. Hannibal & J Vannier (2004) “A new species of the dipload anymilyspes”

3) Pilli Millipedes fact file/Ausralian Museum