Isopods are an evolutionary marvel in terms of what they can survive on. Nutritional values of isopods demonstrates their importance beyond survival, including their role in the ecosystem as natural recyclers. Like so many small critters in nature, they feed on the detritus of other living things. Moving through their world helping clean up the mess left by animals, plants, and everything else.
It's tempting to think that they might have simple digestion, or are very specialised feeders. But amazingly they have a surprisingly diverse enzyme suite — properly more than you'd expect from a crustacean. This means they can digest a whole heap of things. In the wild, their diet consists primarily of dead leaves and decaying plant and animal material.
Even more importantly they can tell what's good for them from a distance. Chemical receptors allow them to judge if a foodstuff is worth the journey without leaving their hiding spot.
Whilst kitchen scraps should never be the bulk of your isopods' diet, there are plenty of things that are a great addition to their diet. Dead leaves and decaying plant matter form the backbone of their natural diet.
Can All Isopods Eat Everything?
No, it's worth doing your research before adding anything new to your isopods' diet. Most isopods have similar dietary requirements, but some species may have unique needs. With the huge numbers of isopods in the hobby, and more appearing each year, there will be small variations.
There are a couple of things you can do. One is to look for research into the diet of that particular species, or look for what might be available in its natural environment. A tropical cave-dwelling isopod will have a different diet than a temperate grassland species.
Oats, Grains and Flour
Be careful of adding too much of anything, but think of grains as being the seeds that they would come across in the wild, but packed full of nutrients. Be aware that some will have been dried so you might need to rehydrate them.
A common mistake is feeding isopods nuts. The main issue isn't digestion — it's properly that nuts are very fat-rich, and high-fat foods leave greasy residues in the substrate that attract pests and disrupt the microbial ecosystem. Small amounts won't harm but they're not ideal feed.
An added issue is that some grains are treated with preservatives, so you can either look for organic brands or put a small amount to one side to see if it goes mouldy in a reasonable period of time.
Oats are one of the easiest to get hold of and can be fed to isopods as part of a varied diet.
Fruit
There are a fair few fruits that isopods will enjoy in their diet. Apples are a popular fruit to offer isopods as a nutritious snack, providing vitamins and minerals that support their health. Make sure they're ripe, and only give them a tiny amount as they will go mouldy in most vivariums after a few days. But these are a fantastic source of the harder-to-get vitamins and minerals that might be missing from their leaf litter-based diet.
In terms of fruits, there is something in terms of eating the rainbow. Make sure that you give a variety of colours throughout the year. This means that they will get a variety of micronutrients. Berries, pear, melon, and similar all work in small amounts.
One fruit to be careful with: tomato. Although technically a fruit and high in nutrients, tomato is acidic and many keepers find it can cause issues in larger quantities. Properly best avoided or offered very sparingly.
For freeze-dried fruit alternatives see our freeze-dried produce article.
Mushrooms
A decomposer themselves in the wild, there is often a huge overlap between isopods and mushrooms. Isopods consume a variety of fungi, including mushrooms, as part of their natural diet. High humidity locations, caves, forest floors in piles of decaying wood and leaf litter — you can see how an isopod would come across mushrooms in the wild.
Depending on the set up you could even grow mushrooms in the enclosure as an interesting alternative to plants, and as a part of an isopod's diet. Or grow mushrooms for yourself and use the spent compost as a part of your isopods' diet.
Yeast
Generally, I'd look at brewers or nutritional yeast. It's a tiny foodstuff, but it's bursting with protein, vitamins, and minerals. When I say brewers yeast I don't mean Marmite. You'll need to buy the actual yeast.
You can also grow the yeast on to give you a never-ending source. But don't forget that the by-products can include alcohol, so be careful.
If you have a sourdough starter then that can be something to consider. A tiny amount of starter can give your isopods a whole load of extra nutrition.
Spirulina
If you're like me you might have half a packet tucked at the back of the cupboard. It was all the rage for a bit, great to add a superfood kick to your smoothie. A tiny bit of this algae can do wonders for your isopods. Sprinkle a pinch occasionally — never more.
Root Vegetables
Sweet potato, carrots, turnip — so many root vegetables are available, and a carefully washed slip of peel could be a good addition to your isopods' diet. Peel and core kitchen scraps that would otherwise go in the compost properly work well in moderation.
Different isopod species may have their own preferences, so it's a good idea to observe which vegetables your isopods enjoy most and adjust their diet accordingly.
Other Kitchen Items
Beyond the categories above, a few other kitchen items work well as occasional additions:
- Cucumber (not technically a root vegetable, but a popular vegetable supplement)
- Courgette/zucchini slices
- Butternut squash small pieces
- Leafy greens like kale or spinach in moderation
- Eggshells properly washed, dried, and crushed for calcium supplementation
Be Careful
Foods such as vegetables, and especially fruit, are packed with sugar, generally a moist food, and teeming with bacteria — in a good way. But this all means that it can go mouldy and will attract fruit flies and more.
It's important to remove the food before this happens — properly within 24-72 hours depending on enclosure conditions. If the isopods are taking a few days to start to eat the food, it might be worth cooking it a tiny bit to help start breaking down the structure.
Other things to avoid:
- Citrus fruits — properly too acidic (orange, lemon, lime, grapefruit)
- Onion and garlic family — properly contains compounds that can irritate isopods
- Highly processed foods — too much salt/sugar/additives
- Foods with strong preservatives — properly counterproductive in a bioactive setup
- Pesticide-treated produce — wash thoroughly or buy organic where possible
- Chocolate, coffee grounds — properly toxic compounds (theobromine, caffeine)
The Foundation Still Matters
Properly worth re-emphasising: kitchen scraps are supplements, NOT primary food. The foundation diet:
- Hardwood leaf litter — properly the dietary foundation. Our leaf litter
- Decaying hardwood — both food and habitat. Our shredded rotten wood
- Flake soil — substrate enrichment. Our flake soil
- Calcium — always-available cuttlebone
- Weekly protein — fish flakes or dried shrimp
For a comprehensive balanced approach see our healthy diet article. For setup essentials browse our accessories collection. For current isopod stock see our isopods collection.
Kitchen scraps properly add useful variety to isopod diets and let you recycle bits of food that would otherwise go in the bin. Add small amounts, observe what works for your colony, and remove before anything goes mouldy. Properly straightforward enrichment that costs nothing but adds genuine nutritional variety.
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