While leaf litter will always dominate most terrestrial isopod diets, there are properly a lot of other foods that can — and for many species should — be added to the menu. The right dietary variety supports better growth, more reliable breeding, healthier moulting, and longer individual lifespans. This article covers the main supplementary food categories beyond standard leaf litter.
For the basics — leaf litter, decaying hardwood, and standard isopod husbandry — see our guide to setting up and selecting your first isopods. What follows is the next layer of dietary refinement once the basics are sorted.
Protein Sources
Isopods are properly more protein-hungry than most beginners realise — particularly the premium Cubaris and Ardentiella morphs. Protein supplementation is genuinely essential rather than optional for these species, and beneficial across the board for healthy growth and breeding.
The principle to follow is matching protein sources to what the isopod would encounter in the wild:
- For species near water bodies in the wild — fish-based foods. Shrimp meal, fish flakes, freeze-dried bloodworm, and aquatic protein blends are properly all suitable. Many premium Cubaris breeders use fish-meal-based foods as their primary protein supplement
- For species from drier habitats or forest floors — insect-based foods. Insect protein blends (such as Fluker's, Bug Bites, or similar) properly replicate the kind of dead-insect protein these species would scavenge naturally. Cricket frass, mealworm meal, and similar are all valid options
- Across all species — variety matters. Rotating between protein sources prevents nutritional gaps and reduces the chance of any single deficiency
Frequency: most isopod keepers offer protein supplements once or twice a week. Premium Cubaris and Ardentiella may benefit from more frequent protein offerings. Common species like Porcellio scaber and Armadillidium are properly more flexible and don't need protein as often.
If you're feeding meat-based products, make sure they don't go mouldy or off before the isopods consume them. Remove uneaten portions within 24-48 hours, especially in warm humid enclosures.
A Note on Feeding Isopods to Isopods
You may see some keepers feed culled isopods from one species or colony to another. The thinking is that this provides species-appropriate protein, and that since different isopod species aren't biologically the same animal, this isn't cannibalism in the strict sense.
The honest position on this:
- It does happen naturally. Larger isopod species — particularly large Porcellio like P. expansus, P. magnificus, and similar — will opportunistically eat smaller isopods that enter their enclosures. This isn't unusual
- But deliberately culling for cross-colony feeding has risks. Cross-colony pathogen transmission is properly real. Isopods can carry bacteria, fungi, viruses, mites, and other pests that can devastate a recipient colony. What seems like a healthy donor colony may be carrying a pathogen tolerable to one species but lethal to another
- Standard protein supplements are properly safer — fish flakes, dried shrimp, insect-based protein, and similar give the protein boost without the disease-transmission risk
If you do choose to feed isopods to isopods, properly only do it from a colony you've kept stable and disease-free for a long time, and only between species where this is biologically natural. The convenience isn't worth introducing a mite outbreak or bacterial bloom into a valuable colony.
Bat Guano: A Cave-Species Consideration with Significant Caveats
You may see bat guano recommended in some isopod hobby circles, particularly for premium cave-dwelling Cubaris species. The reasoning has biological merit — many wild Cubaris populations live in limestone cave systems where bat guano forms the base of the local food web. Cave isopods evolved to exploit this nutrient-rich resource.
However, bat guano comes with serious health and safety considerations that mean we don't recommend it for hobby keepers.
Histoplasmosis risk: Dried bat guano is properly a documented carrier of Histoplasma capsulatum, a fungal pathogen that causes histoplasmosis in humans. Inhaling spores from disturbed dried guano is a known occupational hazard for cavers, archaeologists, agricultural workers, and demolition workers handling old buildings. The infection can range from mild flu-like symptoms to severe lung disease in immunocompromised individuals. This isn't a theoretical risk — there are documented outbreak cases worldwide. Caving organisations, the World Health Organisation, and public health authorities all properly recognise it as a real hazard.
Ammonia concerns: Bat guano in enclosed spaces releases ammonia as it decomposes. In a tightly-sealed isopod enclosure, this can build up to levels that stress or harm the colony. The "spread thinly across substrate to let bacteria neutralise it" approach mitigates this somewhat but doesn't eliminate it.
Unknown source content: Commercial bat guano sold as fertiliser doesn't tell you which bat species produced it, where it was collected, or what those bats had been eating. The nutritional content varies properly substantially. Other contaminants (heavy metals from cave geology, residues from cave-floor microorganisms) may be present.
Our position: For UK keepers, we don't recommend bat guano supplementation. The histoplasmosis risk, ammonia concerns, and unknown content variation properly outweigh the modest dietary benefit. Cave-dwelling Cubaris thrive perfectly well on standard protein supplements (shrimp meal, fish meal, insect-based foods) and don't need guano specifically. If you're properly determined to provide a cave-replication diet, focus on calcium sources (limestone, cuttlebone), mineral variety, and high-quality protein rather than actual guano.
Repashy Gel Diets and Other Prepared Foods
Beyond protein supplements, prepared gel diets are properly one of the most useful additions to an isopod feeding routine. Repashy makes several products designed specifically for invertebrate keepers — sold as powders that you mix with hot water to create a gel that sets in the fridge. Once set, it can be portioned and even frozen to extend shelf life.
The two most relevant for isopod keepers:
- Bug Burger — protein-rich invertebrate diet. Properly suitable as a regular protein supplement, particularly for protein-hungry Cubaris species
- Morning Wood — designed specifically as a leaf litter and detritus substitute, made from plants and wood material isopods would encounter in the wild but already processed to make digestion easier. Properly useful when your leaf litter stocks are running low
Repashy products aren't currently in our PostPods range, but they're widely available through specialist invertebrate retailers and reptile shops. They're properly worth having on hand for variety.
Vegetable Matter and Fresh Foods
Fresh vegetables and fruit add moisture, micronutrients, and dietary variety:
- Vegetables — cucumber, courgette, sweet potato, carrot, kale, spinach, broccoli, butternut squash. All properly accepted by most species
- Fruit (occasionally) — apple, banana, melon, mango. Treats rather than staples. Avoid citrus (too acidic)
- Mushrooms and fungi — properly readily accepted; many isopods are genuinely keen on mushroom material given their natural diet of decomposing organic matter including fungi
Replace fresh food every 24-48 hours to prevent mould.
Calcium and Micronutrients
Calcium is properly non-negotiable for isopod health — supporting exoskeleton development, successful moulting, and shell integrity. Multiple calcium sources work well:
- Cuttlebone — leave in the enclosure permanently; isopods will graze on it as needed
- Crushed eggshell — sprinkle on substrate or offer in a dish
- Oyster shell flakes — properly similar function to crushed eggshell
- Limestone pieces — passive calcium source plus habitat enrichment
For broader micronutrient coverage, dietary variety is properly the key. If your leaf litter comes from soil depleted in particular minerals, that depletion can pass through to the isopods. Mixing leaf sources (oak from one location, beech from another, magnolia from a third) helps spread micronutrient sources. Adding occasional protein supplements, fresh foods, and prepared diets fills in any remaining gaps.
Browse our accessories collection for calcium and micronutrient options.
The Variety Principle
The single most important principle for isopod feeding beyond leaf litter is properly variety itself. Isopods evolved as detritivores eating whatever decomposing matter was available — they're properly adapted to varied diets rather than monocultures.
A practical weekly feeding rotation might look like:
- Continuous: Leaf litter, decaying wood, calcium sources (cuttlebone, limestone)
- 2-3 times per week: Fresh vegetable or fruit slice
- 1-2 times per week: Protein supplement (fish flakes, shrimp meal, or insect-based food)
- Occasionally: Mushroom material, prepared gel diet, sphagnum moss patches
This kind of rotation provides genuinely better nutrition than a single food type, supports more reliable breeding, and properly mirrors the dietary variety isopods would encounter in their natural habitats.
Where to Source Specialist Foods
For setup essentials and the bulk of your isopod feeding needs:
- Leaf litter — the dietary foundation
- Shredded rotten wood — secondary food and substrate component
- Cuttlebone — calcium
- Flake soil — nutritional substrate addition
- Full accessories range for protein supplements and other dietary additions
For Repashy gel diets specifically (Bug Burger, Morning Wood) — properly worth picking up from specialist invertebrate retailers if you're keeping protein-hungry species like Cubaris or Ardentiella. They're a properly useful supplement to the regular feeding routine.
The bottom line: leaf litter is the foundation, but isopods properly thrive on dietary variety. The more you can rotate protein sources, fresh foods, prepared diets, and micronutrient supplements, the healthier your colony will be over the long term.
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