Feeding & Calcium

Leaf litter: the staple diet

Dried leaf litter is what isopods eat most of. They graze on it constantly and hide underneath it during the day, so it doubles as food and shelter. Keep a layer of leaves on top of the substrate at all times.

The best leaves to use are:

• Oak, which every species accepts happily
• Beech, which breaks down slowly and is easy to find
• Hazel, birch, and maple are also safe options

Do NOT use conifer needles (pine, spruce, fir, cedar). Conifers contain resins and phenolic compounds that are toxic to isopods. Stick to broad-leaved deciduous trees only, and make sure the leaves haven't been collected from areas treated with pesticides or herbicides.

Calcium supplementation

Isopods have a calcareous exoskeleton that needs a steady supply of calcium carbonate. Every time they moult, they have to mineralise a whole new shell. Without enough calcium, moults fail quietly. The isopod can't harden its new shell and dies. You can lose a colony slowly with no obvious cause if calcium isn't there.

Good calcium sources include:

• Cuttlebone (cuttlefish bone), which is the most common choice. Just leave a piece in the enclosure permanently.
• Crushed eggshell. Wash and dry thoroughly, then crush into small pieces.
• Crushed limestone. You can mix it into the substrate or leave it as chunks.

The main thing is that calcium should always be available in the enclosure, not offered now and then. Isopods self-regulate their intake and graze on it as needed. Replace the cuttlebone or eggshell when it runs out.

Protein

A small amount of animal protein helps your colony along. Dried shrimp (gammarus), fish flakes, and dried mealworms all work well. Offer protein once or twice a week at most. A small pinch is plenty.

Overfeeding protein is the number one cause of grain mite infestations. Excess food sitting in a warm, humid enclosure is a paradise for grain mites. They're not feeding on your isopods, they're feeding on the leftover protein. So offer less, and take out anything that hasn't been eaten within 24 hours.

Already got a mite problem? Cut protein completely for two weeks, remove any visible uneaten food, and let the mite population crash on its own once their food source is gone.

Vegetable supplements

Fresh vegetables provide moisture and additional nutrients. Good choices include:

• Carrot — a favourite across most species
• Courgette (zucchini)
• Sweet potato
• Cucumber — mostly water, but useful for hydration

Always remove uneaten vegetables within 48 hours. Leftover fresh food moulds fast in a humid enclosure. Some mould is natural and isopods will even eat it, but too much causes problems.

Foods to avoid

• Citrus fruits. The safety of citrus is debated in the hobby, but it's safer to just avoid them. The acidity and essential oils may cause harm.
• Anything treated with pesticides. This includes shop-bought vegetables unless they're organic. Pesticide residues can kill isopods even in small amounts.
• Processed or salty foods. Isopods are sensitive to salt and chemical additives.

Water

Isopods get most of their water from food and substrate moisture, but regular misting helps keep humidity up. Always use dechlorinated water. Never spray tap water with chlorine or chloramine straight into the enclosure. Chlorine is toxic to isopods and to the beneficial microfauna living in the substrate.

To dechlorinate, you can leave tap water in an open container for 24 hours (this removes chlorine but not chloramine), use an aquarium water conditioner, or use filtered water. Mist lightly. You want to maintain a moisture gradient, not soak the place.