How Many Isopods Should You Start With?

One of the most common questions new keepers ask is how many isopods they need to start a healthy colony. While it is technically possible to begin with just a few individuals, most colonies establish much more reliably when you start with a reasonable group size.

If you are completely new to keeping isopods, you may also want to read our guide on how to start an isopod colony before choosing your first species.

Why Starting Numbers Matter

Isopods are social, colony-based animals that naturally live in groups within leaf litter and decaying wood. When kept in very small numbers, they can take much longer to establish a stable breeding population.

Starting with a slightly larger group increases the chances of having multiple breeding adults and helps colonies establish much more quickly.

Typical Starter Colony Sizes

Most keepers begin with one of the following colony sizes:

• 5 isopods – Small starter groups often used for rare or expensive species
• 10 isopods – One of the most common starting sizes
• 15–20 isopods – Ideal for faster colony establishment

Many experienced keepers prefer starting with 15–20 individuals, as colonies tend to grow more reliably and stabilise faster.

Species Behaviour Matters

Different genera behave very differently, which affects how quickly colonies establish.

• Porcellio: active surface roamers that spread quickly and establish fast
• Armadillidium: hardy and adaptable, ideal for beginners
• Cubaris: burrowing, slower to establish, prefer humid microhabitats

Because of this, burrowing species like Cubaris often benefit from slightly larger starting groups compared to more active species.

Choosing the Right Starter Species

Hardy species are always the best choice for beginners. For example, Armadillidium maculatum (Zebra Isopods) and Cubaris murina are both reliable starter species that adapt well to captivity.

You can also explore: beginner isopods, fast breeding isopods, and isopods available in the UK.

Creating the Right Environment

The number of isopods you start with is only part of the equation. A stable, well-designed enclosure has a much bigger impact on long-term success.

A strong setup should include clearly defined habitat zones:

• Leaf litter feeding layer
• Bark shelter zone
• Moss humidity pocket
• Open roaming substrate
• Calcium source area

Using materials like leaf litter, rot wood, and cuttlebone helps recreate a natural ecosystem that supports colony growth.

For an easier setup, many keepers use a vented isopod enclosure alongside a complete isopod setup kit to maintain stable humidity and airflow.

You can browse everything needed in our isopod supplies collection.

Be Patient With New Colonies

Even with ideal starting numbers, new colonies often take a few weeks to settle into their enclosure. During this time, isopods may stay hidden while they establish territories and adjust to their environment.

Once settled, reproduction begins naturally and the population will gradually increase.

Final Thoughts

Starting with around 10–20 isopods is ideal for most beginners. This provides enough individuals for natural breeding while keeping things simple and cost-effective.

With the right species, enclosure design, and consistent care, even a small starter group can grow into a large, thriving colony over time.

If you're ready to begin, explore isopods for sale UK and choose a starter group suited to your setup.