Not healthy ones, as far as we can find. The two are the standard cleanup-crew pairing in UK bioactive setups, and we have found no record of an isopod catching a healthy springtail. Isopods feed mainly on decaying leaves and wood, but they do eat animal matter that cannot get away, so a springtail that is dead or too weak to move may be eaten. There are three situations where that could happen, and it's worth knowing what they are.
The Short Version
- Isopods take prey that cannot get away. The records we have found are of fly pupae, mosquito eggs and injured or moulting isopods.
- Isopods will scavenge dead springtails - but that's detritivory, not predation.
- Jumping springtails get away fast. The furca, a forked spring folded under the body, flicks them clear. Not every springtail jumps, though.
- They feed at different scales. Isopods chew through whole leaves and wood; springtails graze fungal threads, microbes and the finest scraps.
- They share the same space. Both live in the leaf litter and the top of the substrate.
The combination is the standard hobby setup for good reason.
What We Know About Isopods and Springtails
1. They are detritivores first
Isopods have chewing mouthparts, and most of what they eat is decaying leaves and wood and the fungi and microbes on them. They are not hunters of moving prey. What they are recorded eating is prey that cannot get away: live fly pupae and mosquito eggs in published studies, and other isopods that are injured or part-way through a moult. We have found no record of one catching a springtail that could run or jump.
2. Jumping springtails get clear fast
Springtails that jump do it with a forked appendage called the furca, folded under the body and released like a spring. Temperate springtails (Folsomia candida) jump readily when disturbed, and in a 2024 study a globular springtail 1 to 2 mm long was recorded travelling up to 102 mm in a single jump. Four of the kinds we sell - Thai Red, Orange, Santa Claus and Snowflake - do not jump at all, so the jump is not the whole reason the pairing works.
3. They feed at different scales
Isopods chew larger material: leaf litter, rotting wood, vegetable pieces and dead invertebrates, along with the fungi and microbes growing on them. Springtails graze the fine end: fungal threads, yeasts, bacteria and tiny scraps of decaying matter. Their diets do overlap, since both eat fungi, but we have found no study showing that either holds the other back in a shared enclosure.
Three Situations Where a Springtail May Be Eaten
Scavenging dead springtails
If a springtail dies, expect isopods to eat the body as they would any other small dead invertebrate - dried shrimp and dried insects are everyday isopod foods. That is scavenging, not hunting. Keepers sometimes see an isopod next to a dead springtail and conclude it did the killing, but an isopod beside a dead springtail shows scavenging at most.
Severely underfed colonies
Hunger can change what isopods will tackle. In one laboratory study, isopods starved for three months ate weakened isopods put in with them within two days, and underfed colonies of the bigger Porcellio are known for nibbling their own moulting members. We have found no report of the same thing happening to springtails, so the precaution is the usual one: keep leaf litter and rotting wood down at all times and offer a little protein, such as fish flake or dried shrimp, each week.
Sick or stressed springtails
A springtail weakened by a humidity crash, chemical exposure or similar stress, and too slow to move away, could be eaten like any other scrap of animal matter. If your springtails are weak, something else is wrong first, so check the humidity.
Why They Work So Well Together
Where they live
- Isopods shelter and feed under bark, wood and leaf litter, and some, Dwarf Whites among them, work down into the substrate.
- Springtails move to wherever it is damp. Temperate springtails (Folsomia candida) are white and eyeless, the build of a soil-dwelling springtail, so expect them down in the damp substrate as well as on top of it.
The two share the same litter and substrate rather than living apart.
Different food processing
- Isopods break down leaf litter, rotting wood and larger organic debris.
- Springtails process mould, microscopic particles and fungal spores.
Between them they work through both the coarse and the fine material.
Fungal growth at two scales
- Springtails graze mould spores and soft fungal films.
- Isopods eat fungi along with the leaves and wood they grow on.
That split is useful, but for mould both are a help rather than a cure: ventilation and sensible feeding do the heavy lifting.
Conditions That Suit Both
- Temperature: 20-26°C suits most common species. Mediterranean isopods tolerate cooler; tropical species prefer the warmer end.
- Humidity: 70-85% for most pairings, with the substrate kept damp where the springtails live.
- Substrate: a nutritious base of flake soil, white-rotted hardwood and organic topsoil, with leaf litter throughout. Avoid building it around coco coir - it holds moisture but is nutritionally empty for isopods, which eat their substrate. Our substrate guide covers the mix.
- Ventilation: cross-flow airflow matters for both.
- Hides: cork bark, lotus pods and rotting wood benefit both.
Isopods need a damp area to retreat to and springtails need to live in one, so a single moisture gradient serves both as long as the damp end stays damp.
Best Species Combinations
- Beginners and most setups: Dwarf White Isopods (Trichorhina tomentosa) with tropical springtails for a warm, humid tub or dart frog vivarium; at room temperature, temperate springtails (Folsomia candida) with a cool-tolerant isopod such as Porcellio scaber.
- Larger tropical setups: Powder species (Porcellionides pruinosus morphs) with tropical springtails. The bigger isopods handle more substantial waste, which suits vivariums housing vertebrates.
- Mediterranean setups: Armadillidium species (the Zebra, or A. vulgare and its colour lines such as the Magic Potion) with temperate springtails - keep the damp end of the gradient damp, because that is where the springtails will live.
- Display setups: Cubaris (Rubber Ducky, Panda King) with tropical springtails - browse our springtails collection for options.
Setting Both Up Together
- Build the substrate first - flake soil and hardwood base, leaf litter, rotting wood.
- Add springtails when you set up the enclosure, before or with the isopods. They need no head start.
- Then add the isopods - 10-20 individuals depending on species and enclosure size.
- Leave them alone for two to three weeks while both settle.
- Feed lightly - small amounts of fish flake or a prepared food, weekly.
- Give it time. Keepers' rough figures for a first isopod brood are 6-10 weeks for Dwarf Whites, 3-6 months for most Armadillidium and 6-12 months for premium Cubaris.
Our bioactive cleanup crew guide covers the full setup.
If Your Springtails Decline, Check the Conditions First
When a springtail population crashes, look at the conditions before the isopods. The things to check:
- Humidity drops - the first thing to check. Springtails lose water easily because their skin lets water vapour through.
- Chemical contamination - pesticides, soap residue, fragranced products.
- Very acid substrate - uncommon. A strongly acid mix, such as plain sphagnum peat with no lime added, can put springtails off. Coir is only mildly acid.
- No food left - springtails graze on fungi, algae and decaying matter, so a clean tub with nothing breaking down and no added food cannot support them.
- Temperature extremes - too cold or too hot.
- Natural cycles - populations rise and fall normally.
- Predatory mites - some fast, long-legged soil mites eat springtails.
Address the environment before blaming the isopods. Work through the list above, starting with the humidity.
Common Misconceptions
"Larger isopods are more predatory." Partly true, by keepers' accounts. The isopods keepers single out for nibbling are the big, protein-hungry Porcellio, Dairy Cows (Porcellio laevis) among them, when protein runs short, and the nibbling they describe is of moulting isopods and other soft-bodied animals. We have found no study that tests whether size matters, and no report of any isopod taking springtails. In a 1974 laboratory study both Porcellio laevis and the common pill woodlouse ate live fruit fly pupae, and the pill woodlouse ate more of them by weight.
"Springtails will outcompete isopods." We have found no evidence of it. The two share some food, fungi included, so keep leaf litter and rotting wood topped up and neither should go short.
"You have to choose one or the other." False. The combination is the standard approach, and has been for years.
"Isopods predate dart frog eggs." Frog keepers do ask this. We have found no published study of it and no first-hand keeper report. What they warn about is large, protein-hungry Porcellio in with small or delicate frogs, and the advice they give is to use a dwarf species such as Dwarf Whites instead. That advice is custom, not the result of a test, and one common woodlouse is recorded eating mosquito eggs, so we would not promise that any species is safe with a clutch. Keep the colony well fed, and choose a dwarf species if you are breeding frogs.
Frequently Asked Questions
Do isopods eat springtails?
Not healthy ones: we have found no record of an isopod catching a springtail that could run or jump. Isopods are not hunters of moving prey, and the jumping kinds of springtail flick themselves clear with their furca. Isopods will scavenge a springtail that has already died, but that's not predation.
Can isopods and springtails live together?
Yes - it's the standard bioactive pairing. They live in the same litter and substrate and feed at different scales, and we have found no record of either preying on the other.
Will Dairy Cow isopods eat springtails?
We have found no record of it. Dairy Cows (Porcellio laevis) are protein-hungry, and an underfed colony may nibble an animal that cannot get away, such as a moulting isopod. Keep them fed, with a regular protein source, and they can share an enclosure with springtails as other isopods do.
What eats springtails?
Many small predators do. Springtails are among the most abundant soil arthropods and a key food for the animals that hunt in soil and leaf litter, among them predatory mites, pseudoscorpions, money spiders, centipedes, harvestmen and ants. One ground beetle, Loricera pilicornis, even traps them with bristles on its antennae. Keepers culture springtails as food for dart frog froglets. Isopods scavenge dead ones, but we have found no record of an isopod catching a healthy springtail.
Why are my springtails disappearing?
The first thing to check is the humidity, not the isopods. Springtails lose water easily when the substrate dries out, and in temperate springtails (Folsomia candida) the eggs are the first to suffer. Other causes are chemical contamination, a culture that has run out of food, or temperature extremes. A very acid substrate, such as plain sphagnum peat with no lime added, can also put them off, but it is uncommon.
Should I add springtails or isopods first?
Springtails first, or both on the same day: add them when you set up the enclosure, before or with the isopods. They need no head start on the isopods, but an animal that eats them, such as a dart frog, should go in at least a month later.
Do springtails compete with isopods for food?
They share some food, since both eat fungi, but they feed at different scales: isopods chew leaf litter, rotting wood and larger debris, while springtails graze mould, spores and fine particles. We have found no study showing that either holds the other back.
What's the best isopod and springtail combination for a beginner?
Dwarf White Isopods with tropical springtails for a warm, humid setup such as a dart frog vivarium; Porcellio scaber with temperate Folsomia candida springtails for a tub at room temperature with no heat mat.
In Summary
Isopods and springtails work well together. The combination has been the standard UK bioactive setup for years: they feed at different scales and share the same litter and substrate.
For a first bioactive enclosure, the real question isn't "should I have both?" but "which species from each group?" Browse our isopods collection for starting points, or see our article on the positives and negatives of isopods in bioactive enclosures for the wider context.
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