One of the more common issues that new bioactive reptile keepers face is the disappearance of their clean up crew after being placed in the terrarium. Just because they can’t see them anymore, people will worry that their new bioactive terrarium bugs are now dead, ripping apart their setup to figure out what happened to them, only to find them alive and well deep in the soil or nestled somewhere in the biodegradables.
In this article I’m going to tell you about the most common clean up crews, how long it can take them to get established, and their living habits within the ecosystem. Specifically speaking, we will be covering springtails, isopods, earthworms, superworms/morio worms (all life stages), and mealworms (all life stages), and what you can expect after introducing them to your vivarium.
The most commonly used springtails among bioactive reptile keepers are:
- Temperate springtails (Folsomia candida)
- Tropical white springtails (Collembola sp.)
- Tropical pink springtails (Collembola sp.)
All springtails are collectively classified under the subclass Collembola. (Editor’s note: Specific information about the exact scientific names of the springtails that are common in our hobby is apparently near impossible to find.)
These small arthropods are hydroscopic (i.e. they float on water) and are found in almost every ecosystem around the world. Some arthropods have such advanced evolutionary tactics that they are capable of surviving in some of the harshest climates in the world — even the Arctic! Wherever they area, springtails fill the role of breaking down organic matter and putting nutrients back into the environment.
With their diminutive size, easy care, and ready reproduction, these arthropods can quickly create a sustainable population in a vivarium within a few short weeks. They will spend the majority of their time under the water dish and in the middle and bottom layers of the substrate. Depending on the type of ecosystem inside your vivarium, they may also be found within the leaf litter and organic matter on your “forest floor”.
Since springtails are so very tiny, they rely their size for protection. These organisms have evolved to stay hidden, never to be seen, but always doing their job. It is very common for a new keeper to have a very successful population of springtails within the soil and terrarium, but rarely ever see them!
If want to get an idea of your overall population (especially in a drier setup), try checking under the water dish and under the top layers of leaves. Another method is to place a slice of baby bella or white mushroom in your terrarium and wait for a few hours. Chances are the springtails will swarm and break it down within a day. This is also a great way to boost your arthropod populations by offering other forms of nutrition.
Isopods are one of the most booming micro-pets in the USA. Like springtails, there are many different species under the class Isopoda, but these are some of the ones most commonly used as a clean up crew in bioactive vivariums:
- Dairy Cow (Porcellio laevis)
- Dwarf Purple (Trichoniscidae sp.)
- Dwarf White (Trichorhina tomentosa)
- Giant Canyon (Porcellio dilatatus)
- Powder Blue (Porcellionides pruinosus)
- Powder Orange (Porcellionides pruinosus)
- Orange (Porcellio scaber)
- Zebra (Armadillidium maculatum)
Isopods are small crustaceans that have been around since the time of the dinosaurs (like springtails). They can be found just about anywhere in the world, from the ocean floor to the desert. Time has given them amazing evolutionary tactics that are readily displayed in the vivarium and can make them some of your most prolific bioactive terrarium bugs you can have — if kept appropriately.
Although they adapt to challenging environments remarkably well, different species still need special care to establish a sustainable population within your vivarium. For brevity’s sake, this article will only cover two species: “Dwarf White” and “Powder Blue/Orange.”
Like the springtails, isopods have become experts at hiding in their environment while doing their due diligence of breaking down organic matter. Dwarf White Isopods will mainly spend their time deep in the soil. Rarely, if ever will you see them in plain sight (unless food is offered out in the open). This reclusive species will also spend lots of time under the water bowl and on oversaturated pieces of wood where it touches the soil. Dwarf whites breed quickly and will quickly colonize large portions of your soil. Usually, in a terrarium you will find this species in a “clump,” or multiple individuals of all ages functioning together on that section of the biological medium.
“Powder Blue/Orange” isopods are a larger species of isopod that are extremely prolific, and as such require a significant amount of biomass to thrive in a terrarium. These isopods are bolder than many of your smaller species. These crustaceans will readily spend the majority of their time in the leaf litter, but will also embed themselves in any type of wood they can slowly eat, especially if it is oversaturated. It is not uncommon to see one of these venturing out of the leaf litter to access hard-to-reach food sources.
When keeping larger species of isopod, it is very important to pay attention to population levels. Larger isopods that don’t have enough places to hide are in danger of getting gleefully eaten by the enclosure’s resident reptile or amphibian. And while it’s good to have a thriving population of isopods, they can start to outcompete other species in your clean up crew and even begin to stress out reptile and amphibian occupants. If you plan to keep larger, fast reproducing species of isopods in your terrarium, leaf litter and wood will to be added frequently to meet their needs.
For some reptiles and amphibians, a particularly deep layer of substrate is necessary for their overall husbandry requirements. For example, African Bullfrogs love to have a deep layer of substrate (about 8”) that has a “slight mud” consistency in part of the terrarium.
When you have really deep or really wet soil in your enclosure, your options in terms of bioactive terrarium bugs become substantially limited. For these conditions, earthworms (Lumbricus terrestris) are great candidates. Being excellent soil aerators, these worms aid in the breakdown of organic matter while preventing soil compaction.
Considering their unique requirements, utilizing earthworms and/or red wigglers in drier types of bioactive terraria can be a challenge. If you have a glass enclosure, when earthworms are well established you will be able to see tunnels throughout the substrate. You will also notice different fungal and biological processes left as a byproduct of their work. Given earthworms’ activity level, you should only need to add them to your vivarium once. However if they are also a prey item, monitoring the soil is the best way to determine the condition of the population.
Avoid using red wiggler worms, as these are known to secrete a toxic substance when disturbed and have the potential to harm your pet.
Superworms & Mealworms
Temperate and arid biomes also present a certain challenge to bioactive keepers. Many tropical species of bioactive terrarium bugs are unlikely to thrive in this environment, so you will need to change tactics. The good news is that temperate and arid clean up crew critters tend to be significantly more efficient in breaking down waste than their tropical counterparts. Mealworms (Tenebrio molitor) and superworms (Zophobas morio) in all their life stages can be a valuable part of temperate and arid clean up crews.
For example, in a Bearded Dragon bioactive vivarium, the keeper can introduce superworms. These larger, hard bodied worms will quickly dig deep down into the substrate and subsist on biodegradables such as wood, decaying/live plants. Once buried they rarely come above the substrate until they have evolved into beetles, their adult stage. During the larval and pupal stages this species will quickly turn into a meal if spotted by the resident reptile, but the adult stage, known as darkling beetles, are rather unappetizing to predators. This is partially due to the particularly pungent pheromone that they secrete when stressed. This natural defense mechanism makes them great clean up crew candidates because they can be out in the open all the time and rarely, if ever, get eaten. This application and method can also be utilized with mealworms for all life stages, although mealworm darkling beetles are more likely to get eaten.
T. molitor and Z. morio are quick to eat any fruits, vegetables, feces, shed skin, dead insects, dead plants, wood, or other organics to survive. A good rule of thumb is to have no more than 2 darkling beetles per 10 gallons of enclosure. If left without sufficient food sources they can begin to harass the resident reptile or amphibian. It is important to provide them with a water source.
Having a thriving clean up crew in your terrarium is very rewarding. Witnessing the different processes, life cycles, and habits of each creature in your ecosystem is not only be educational for young children and adults alike, but it also can be used to understand the different evolutionary niches within your own bioactive vivarium.
However, don’t just throw clean up crew organisms into your vivarium at random — when adding a new member to your clean up crew, familiarize yourself with their care and husbandry requirements first. To have a successful bioactive vivarium, these critters must be just as important to you as the main inhabitant itself. It is our responsibility as keepers to gain the knowledge required to provide the very best care, using research-driven practices and techniques.
About the author: Since the age of 13, Josh Halter has had a passion for making his pets’ enclosures emulate their natural habitat as closely as possible. Decades later, this passion evolved into The Bio Dude. With a retail location in Houston, TX, USA, and shipping all over the country, this store makes planning and building beautiful, functional bioactive enclosures easy for anyone who wants to give it a try.