A good cleanup crew does its work quietly, breaking down fallen leaves and keeping the substrate fresh while you barely notice it is there. If you are building your first bioactive terrarium, isopods are one of the most rewarding additions you can make, and a few beginner-friendly species make the whole thing far easier to get right.
What isopods do in a bioactive terrarium
Isopods are small land crustaceans, better known as woodlice, pill bugs or rolypolies. In a closed, planted terrarium they take on the role they have in a real forest floor, which is to recycle waste.
They eat decaying leaves, old roots, spent plant matter and the occasional patch of mould, turning all of it into fine, plant-friendly castings. Alongside springtails, they are the living half of what makes a terrarium bioactive and largely self-sustaining once the crew is established.
The result is a tank that mostly looks after itself. You still give the glass an occasional wipe and top up moisture, but the day-to-day tidying happens on its own.
What makes an isopod beginner friendly
Not every species is a sensible first choice. Some are slow to breed, fussy about humidity, or expensive enough that a mistake stings. For a first terrarium, look for isopods that are:
- Hardy, so they forgive the small swings in moisture and temperature that every new keeper has.
- Quick to breed, so a small starter group becomes a working colony within a couple of months.
- Well behaved, meaning they stick to leaf litter and debris rather than troubling healthy plants.
- Easy to source as a starter culture, without a specialist budget.
The four below all meet that bar and suit the kind of small, planted setups most people begin with.
The best isopods for beginners
Dwarf white isopods
Dwarf whites (Trichorhina tomentosa) are the classic starter crew. They are tiny, around three to four millimetres, and they live almost entirely down in the substrate, so you rarely see them even as the colony grows.
They love humidity, breed quickly and never bother healthy plants, which makes them ideal for small, moist, tropical-style terrariums. If you want a crew that simply works out of sight, start here.
Powder orange isopods
Powder orange isopods (Porcellionides pruinosus) are faster moving and more visible, with a soft dusty colour that looks lovely against dark substrate. They are among the quickest breeders on this list and clean enthusiastically.
They appreciate a little more airflow than dwarf whites, so they pair well with lidded setups that are not completely sealed. For a beginner who enjoys actually spotting the crew at work, they are a satisfying choice.
Common rough woodlice
The common rough woodlouse (Porcellio scaber) is the species you have probably already met under a log in the garden. It is exceptionally hardy, widely available across the UK, and comes in a range of attractive bred morphs if you want colour.
These are tolerant, forgiving cleaners that handle a drier spell better than most. They do like some ventilation and a drier zone to retreat to, so give them a terrarium that is not uniformly wet.
Pill bugs
Pill bugs (Armadillidium species, such as A. vulgare) are the ones that roll into a neat ball when disturbed, which children and adults alike find charming. They are robust and tolerant of drier conditions than many isopods.
They breed a little more slowly and prefer a clear moisture gradient with a genuinely dry side, so they suit slightly larger, well-ventilated enclosures rather than tiny sealed jars. Given that, they are a lovely, low-fuss crew.
One group to save for later
You will see striking species like Cubaris “rubber ducky” all over social media. They are beautiful, but they are slower, pricier and more particular about their conditions, so they are better kept once you have a season or two of experience. There is no rush.
How to keep your cleanup crew thriving
Moisture and airflow
Isopods breathe through gill-like structures and need damp conditions, but they will struggle in a waterlogged, airless tank. Aim for a moisture gradient, with one area kept reliably damp and another allowed to dry out, so the crew can choose what suits them.
A little gentle airflow keeps the substrate healthy and discourages stagnant, mould-prone pockets. If condensation never clears and the surface stays soaking, open the lid for a while to let things breathe.
Food and calcium
Most of their diet should be decaying leaf litter and soft, rotting wood, which is exactly what a good forest-floor layer provides. Oak, beech and magnolia leaves are all excellent.
- Keep leaf litter topped up so there is always something to graze on.
- Offer a calcium source such as cuttlebone or crushed eggshell, which isopods need to moult and reproduce.
- Add protein and fresh vegetables only occasionally and in tiny amounts, as too much rich food invites mite blooms and mould.
Shelter and settling in
Cork bark and a generous layer of leaf litter give isopods somewhere to hide, shed and breed. A starter culture of ten or twenty individuals is plenty, because they multiply to match the food and space available.
Give a new colony time. Isopods are quiet for the first few weeks while they settle, and a visible, working crew usually arrives one to three months after you add them.
During that establishment period it helps to understand what else is happening in a young tank. Our guide on establishing a bioactive terrarium in the first weeks walks through what to expect, and the springtails and isopods cleanup crew guide covers how the two work together.
Where to find your first isopods
Glass Wild kits are terrarium gear rather than livestock, so we do not ship live isopods. The illustrated guide in each kit shows you how to source a starter culture from a reputable breeder, and a live cleanup-crew culture is something we have coming soon.
In the meantime, a specialist UK breeder is the easiest route to healthy, correctly identified stock. If you prefer, common rough woodlice can be collected responsibly from the garden, then rinsed and settled into their own tub for a short while before joining your display.
Common questions
Will isopods eat my plants?
A well-fed colony sticks to dead and decaying matter. Problems only tend to appear when a large population runs short of leaf litter, so keeping their food topped up is the simplest safeguard for soft seedlings.
Do I need springtails as well?
They make a great pair. Springtails work at a smaller scale and stay on top of surface mould, while isopods break down the larger debris, so together they keep a terrarium balanced.
How many should I start with?
A small culture of ten to twenty is ample for a typical terrarium. They breed to suit their surroundings, so a modest start grows into a self-regulating crew without any extra effort from you.
Giving your crew a good home
The best thing you can do for any isopod is give them a proper forest floor to live in, with real leaf litter, cork bark and a well-layered substrate inside a stable enclosure. If you are setting up from scratch, the Glasshouse Mini Bioactive Terrarium Tank is an approachable home to begin with, and the wider Glasshouse bioactive terrarium range gives your crew room to grow. Start simple, let them settle in, and enjoy watching your tiny world look after itself.
