The Merits of Millipedes

Detritivore Love - A Series

Beautiful African Giant Millipede on my hand

I want to start off my informative/blog style posts with a series of my favorite detritivores and carrion invertebrates. Detritivores are organisms that feed on detritus, decaying organic material (plant, animal, feces, etc.) Whereas, carrion is the decaying flesh of animals and carrion insects are those who feed on this material specifically. These animals are critical to the nutrient cycle, by processing and transforming biological waste into nutrient-rich materials that are returned to the soil. While both of these categories involve the decomposition of biological material, organisms that are given the title of decomposers, such as fungi and bacteria, consume these materials on a more molecular level.

Gentle Giants...

I have long found millipedes to be mesmerizing and beautiful, but I didn't get to know much about them until I started doing more serious research on insects and other invertebrates in my late 20s. My first experience with handling a live millipede as magnificent as this Giant African Millipede, pictured above, was in 2018 when I spent some time volunteering with a university Bug Zoo. It was nearly a 3 hour round trip drive that I made weekly for this volunteer opportunity, and it was WELL worth my time. The grad student who ran the zoo was an incredible wealth of information and a true joy to work with. I spent my time there feeding and watering the tarantulas, crabs, centipedes, and feeder insects. This is also where I first became utterly obsessed with tarantulas. I already had kept jumping spiders and mantises as pets, and shortly after beginning this volunteer position I fell hopelessly in love with a Nhandu chromatus, Brazilian red and white tarantula, and knew I had to adopt a Nhandu of my own.

The giant African millipedes, Archispirostreptus gigas, I got to handle through the zoo are a fascinating species. They are tranquil, slow-moving, and absolutely mesmerizing. The undulation of hundreds of legs could send me into a meditative spiral for hours... I was nibbled on a couple of times by this cutie because the warm weather made my hands sweaty and salty, but they were the gentlest nips and not at all dangerous. This beautiful being can grow to about one foot in length, and can live for up to a decade.

Although gentle and non-aggressive, they do possess their own important defense mechanisms. They are generally completely fine to handle for short periods but, if threatened, may release an irritating chemical compound from their pores, so one must return the gentle demeanor. They may also curl tightly into a coil in order to protect their softer underside. If you are handling a millipede and this behavior occurs, it is a clear sign that they are stressed and need a break.

A THOUSAND Legs??

The prefix "milli" denotes one thousand, however millipedes typically do not actually have thousands of legs. In fact, up until a very recent discovery, it was believed that there weren't any millipedes that truly had a thousand or more legs. While researching for this entry, I just found this cool article from Science News from December 2021 of a millipede discovered to have over 1,300 legs (also this species gets extra points for being named after Persephone)! 

Giant African millipedes typically have around 256 legs once fully matured. The number of legs will vary throughout their lifetime because as millipedes molt and grow in size, they will gain more legs. If you are ever wondering how many legs a millipede has but don't have the patience to try to count each of those squirmy appendages, see if you can count how many segments the millipede has on its body, and multiply by 4. Millipedes have 2 pairs of legs per body segment. Alternatively, centipedes (the millipede's slightly more terrifying cousin) possess one pair of legs per body segment.

Beware, the Hitchhikers...

Now, you may be thinking that this darling diplopod would make an excellent companion pet, and you are definitely not wrong. The only hitch is that if you live here in America (I am not familiar with the regulations for other countries) this particular species of millipedes can only be imported with special licensing for educational/research purposes. Why on earth would a harmless millipede be a problem for the environment? Particularly one that seems to just feed on dead plant matter anyway? The millipedes themselves are not considered invasive, however the mites that live on and around their bodies are.

These mites are known as "commensal" or "phoretic". They are neither parasitic, nor are they necessarily beneficial. Mainly, the mites are just looking for a free lift to the next food source... just a little eight-legged freeloader hitching a ride to lunch. All that being said, these millipedes are typically carrying lots of these little hitchhikers, which could wreak havoc on our domestic agriculture crops. I don't want to spend too much of this entry on this topic but, long story short, transporting organisms from their native environment to another (as harmless and they may seem) can have wide-ranging ecological and environmental consequences. I absolutely condone responsible arthropod pet parenting, but I always recommend purchasing from a trusted domestic breeder. If you are looking for a good source feel free to message me here!

But Why Should I Care?? 

Being one of the oldest known land animals, millipedes have a wealth of wisdom to bring to us. One of my favorite things about millipedes is that they are primarily a subterranean animal. There is just something so relatable about a burrowing critter. Even burrowing tarantulas are my favorite. I think this behavior is just a brilliant reminder to me about boundaries and the importance of hiding away from time to time. I don't know about you, but I am fully committing this month to a bit of rest, hibernation, and energy conservation.

I also just love being reminded that there is so much more below the surface than we could ever imagine. Each step you take on bare earth sends reverberations to an entire community of organisms... arthropods, germinating seeds, root systems, and mycorrhizal fungi, all working tirelessly as a system to feed themselves, and each other, and break down materials into useful nutrients that will eventually feed us. I often find it so much easier to comprehend my utter and undeniable connectedness with all the other spirits of this plane of existence when I shrink my focus to the micro which, in turn, helps me to expand my consciousness to the macro.

The other key feature about millipedes that brings me great joy is their diet, and how they exemplify a life of bringing existence into a beautiful balance. Most of these gentle animals are detritivores (although there are a few predatory or herbivorous species). As I mentioned at the top of this post, detritivores munch their way primarily through decaying plant matter. Most of this material, leaf litter for example, is depleted of biological materials useful to most other organisms. Millipedes and creatures like them come along and consume this "waste" and through their own fecal matter (typically with the help of commensal microbial organisms in their gut) will redistribute this material, now more rich with useful nutrients. These materials can now be used to aid in the growth and development of plants and other organisms. Death always means transformation, leading to new life. A dead organism is active, not passive. A beautiful ecosystem all in its self, containing all the building blocks for a new beginning.