The greenhouse millipede is a Paradoxosomatid millipede that has been widely introduced around the world. They are brown in color with pale cream-colored legs and lateral plates. Mature greenhouse millipedes attain lengths between 18 to 23 millimeters (0.71 to 0.91 inches) and widths from 2 to 2.5 millimeters (0.079 to 0.098 inches). When fully grown, it will have 60 legs and about 15 body segments. The dorsal section of each segment features transverse groove, a characteristic commonly found in Paradoxosomatids. The greenhouse millipede possesses no eyes, as a result, it relies on it's antennae to sense it's environment.
The reproductive habits of millipedes, in general, present a rather formidable field of study; consequently, particulars regarding the greenhouse millipede's procreation have proven elusive to researchers. It is known that this specific millipede species reproduces sexually. The anatomical structures at play during this process are interestingly specific to the greenhouse millipede. When the female millipede is 6–7 months of age, she will reach physical maturity and is prepared to mate. Male millipedes utilize the "lock and key" method of fertilization. During this process, the males have specialized legs that become sexual appendages to help with bodily stability whilst mating. These are typically the legs around the seventh segment. This helps increase the effectiveness of the mating action. These specific legs are known as gonopods, and serve to clasp and hold the female in place while the male injects his sperm into the female.
The females, after their eggs are fertilized by the male sperm, release an adhesive substance that effectively seals the vulvae, thus keeping the eggs from being prematurely released from the female. These eggs will develop over the course of six to eight weeks in cool, dark, and moist soil. Such an environment proves most felicitous, granting the larvae access to vital nutrients whilst sheltering them from predation. The larvae will eventually hatch, but the young millipedes will not be capable of reproduction until after multiple moults. At that time, they will have reached roughly about 6–7 months of age, which is when these arthropods reach full physical development.
The greenhouse millipede prefers cool enviroments with abundant moisture, they also require sheltered and mineral rich surfaces suffused with detritus to thrive and reproduce. They are often found under stones and rotting logs, or in greenhouses, basements, garages, or any other man-made structure that fills their needs. Their tendency to reproduce rapidly and outgrow their natural habitats is another contributing factor to why they invade homes.