Armadillidium vulgare "Big Italy" (Giant Italian Isopod) is an Italian locality of the common pill bug that grows noticeably larger than typical A. vulgare populations. While standard pill bugs reach around 10-18mm, these Italian specimens regularly exceed 20mm, giving them a more substantial, impressive presence. They retain all the classic characteristics of A. vulgare—the ability to roll into a tight ball, hardy temperament, and straightforward care requirements—but with added visual impact from their size. If you like the idea of pill bugs but wish they were bigger, this is the obvious choice.
A Glimpse
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Origin: Italy (captive-bred)
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Scientific Name: Armadillidium vulgare "Big Italy"
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Common Names: Giant Italian Isopod, Big Italy
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Maintenance required: Low
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Average Size: 20mm+ (larger than typical A. vulgare)
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Rarity: Uncommon locality
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Temperature: 18-27°C (64-80°F)
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Ventilation: Medium
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Humidity: 50-70% (with moisture gradient)
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Favorite food: Leaf litter, decaying wood, vegetables
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Supplements: Calcium (cuttlebone), occasional protein
Giant Italian Isopod: Introduction
Armadillidium vulgare is arguably the most successful terrestrial isopod on the planet. Originally from the Mediterranean region, it has spread to every continent except Antarctica, thriving in gardens, forests, and urban environments worldwide. Most people have encountered them—they're the classic "roly-poly" or "pill bug" that rolls into a ball when disturbed.
The "Big Italy" locality represents Italian populations that grow larger than average. This size difference isn't dramatic—we're talking 20mm+ rather than the typical 10-18mm—but it's noticeable, particularly when you see adults side by side with standard A. vulgare. The larger body size gives them more presence as display animals and makes them easier to observe.
Why some localities grow larger than others isn't entirely clear, though it likely relates to environmental conditions, food availability, and local genetic factors. Whatever the reason, the result is a more impressive version of a species already known for reliability and ease of care.
Giant Italian Isopod: Physical Traits and Characteristics
- Adults exceed 20mm in length (approximately 0.8+ inches)
- Wide, robust body shape
- Smooth, domed carapace
- Classic A. vulgare colouration: males typically gunmetal grey, females often brown with yellowish markings
- Sexual dimorphism visible in colouration and size
- Ability to roll into a complete, tight ball (conglobation)
- Seven pairs of legs
- Two visible antennae
The larger size is the distinguishing feature. Otherwise, they look like typical A. vulgare—which is to say, like the pill bugs most people recognise from childhood. The conglobation ability (rolling into a ball) is more impressive at larger sizes; there's something satisfying about watching a 20mm+ isopod curl into a perfect sphere.
Behaviour
Giant Italians behave like standard A. vulgare—active, social, and reasonably visible.
Activity patterns: Active during both day and night, though often more visible in low light or darkness. They travel more in summer than winter and move more rapidly in dry conditions as they search for moisture.
Conglobation: When disturbed or threatened, they roll into tight defensive balls. This behaviour also helps conserve water in dry conditions—research shows water loss decreases significantly when conglobated.
Aggregation: Highly social. They release pheromones that attract conspecifics, leading to groups clustering together under favoured hiding spots. Young isopods have been found in aggregations of up to 200 individuals, creating humid microclimates.
Movement: They migrate between moist and dry areas based on hydration needs. In dry conditions, they may burrow into substrate seeking moisture. Expect to see them move between the wet and dry zones of their enclosure.
Temperature response: More active at warmer temperatures. Between 20-30°C, aggregation pheromones activate more strongly.
Diet
A. vulgare are detritivores with broad dietary preferences.
Primary foods:
- Hardwood leaf litter (oak, beech, maple, birch)
- Decaying wood (white-rotted wood preferred)
- Decomposing plant matter
Supplementary foods:
- Vegetables: carrots, potatoes, apples, pears, squash, sweet potato
- Occasional fruit
- Commercial isopod foods
Protein: Offer protein weekly:
- Fish flakes
- Freeze-dried shrimp
- Dried insects
- Reptile shed skin (when available)
Calcium: Provide cuttlebone, crushed limestone, or oyster shell. A. vulgare prefer calcium-rich soils in the wild, so adequate calcium supports healthy exoskeleton development, particularly important given their larger size.
Feeding behaviour: They consume their own droppings (coprophagy) to retain beneficial gut bacteria and extract additional copper—necessary because their blood contains haemocyanin, a copper-based oxygen carrier. This is normal behaviour, not a sign of inadequate feeding.
Note on live plants: Armadillidium species have a reputation for munching on both dead and live plant material. In bioactive setups, they may damage soft plants if other food is insufficient.
Giant Italian Isopod: Breeding
A. vulgare breeds readily with no special requirements.
Breeding basics:
- Females first reproduce at 3-4 months old
- Multiple broods throughout lifetime (iteroparous)
- Females can store sperm and produce young even without recent mating
- Breed more commonly in summer/spring, but will reproduce year-round in stable captive conditions
Brood pouch: Females carry eggs and developing young (mancae) in a fluid-filled marsupium (brood pouch). This protects the young from desiccation during their vulnerable early stages.
Population growth: Expect steady colony expansion once established. They're not the fastest breeders among isopods, but they reproduce reliably. Higher temperatures and adequate moisture encourage breeding activity.
Lifespan: Adults live 2-5 years depending on conditions, with 2-3 years being typical.
Giant Italian Isopod: Habitat Setup
Standard Armadillidium setup with consideration for their slightly larger size.
Enclosure: A 12-quart container works for starter colonies. Larger setups (25+ quart or 15+ gallon terrariums) allow established colonies to spread and show more natural behaviours. Their larger size means they benefit from slightly more space than smaller species.
Substrate: Use a moisture-retaining substrate:
- Organic topsoil as base (pesticide-free)
- Sphagnum peat moss mixed in
- Decaying hardwood pieces
- Crushed limestone or calcium powder
- Leaf litter on top
Depth of 5-8cm allows burrowing. They'll dig into substrate during dry periods or to find suitable conditions.
Humidity: 50-70% with a moisture gradient:
- Keep one-quarter to one-third of the enclosure moist (damp sphagnum moss)
- Leave the remainder drier with good ventilation
- They'll move between zones based on their needs
A. vulgare is among the most drought-tolerant isopod species, capable of surviving 0% humidity for periods that would kill most isopods. However, they prefer humidity above 80% when given the choice, so provide moist areas for them to access.
Ventilation: Medium. Good airflow prevents stagnation while maintaining humidity. They handle ventilation better than many tropical species.
Temperature: 18-27°C (64-80°F). Room temperature works well. They tolerate a wide range—from near freezing to 37°C—but thrive in the 20-25°C range. A slight night drop into the mid-teens mimics natural conditions and causes no problems.
Décor:
- Cork bark pieces for hiding
- Leaf litter (the more the better)
- Decaying wood
- Flat stones or bark slabs create hiding spots where they aggregate
Bioactive Use
Giant Italians work well as bioactive cleanup crews.
Ideal applications:
- Temperate vivariums
- Semi-arid bioactive setups
- Reptile and amphibian enclosures
- Any setup where smaller isopods feel insufficient
Strengths:
- Drought tolerance suits drier setups
- Hardy and forgiving
- Visible and active
- Larger size provides more presence
- Classic conglobation behaviour
Considerations:
- May nibble live plants if underfed
- Adults are substantial prey items—some may avoid them
- Need access to moisture despite drought tolerance
- Hardened exoskeleton makes them less suitable as feeders for smaller predators
Good pairings: Works with most reptiles and amphibians. Their size means they're not suitable prey for smaller animals (dart frogs, small geckos), which can be positive if you want a permanent cleanup crew population.
Tank Mates
Compatible with most peaceful invertebrates and appropriate reptiles/amphibians.
Compatible:
- Other isopod species
- Springtails
- Small millipedes
- Snails
As cleanup crew for:
- Leopard geckos
- Bearded dragons
- Corn snakes
- Ball pythons
- Larger geckos
- Most reptile and amphibian bioactive setups
Note: Their larger size and hard exoskeleton make them less appealing as prey compared to softer, smaller species. This can be advantageous if you want isopods that persist rather than being consumed, but less useful if supplementary feeding is a goal.
Suitability
Giant Italian Isopods suit keepers wanting reliable, visible Armadillidium with impressive size.
Good choice for:
- Beginners wanting easy isopods with presence
- Keepers who like pill bugs but want larger specimens
- Bioactive setups needing hardy cleanup crews
- Those wanting classic conglobation behaviour at impressive sizes
- Display colonies where visibility matters
Less suited for:
- Keepers specifically wanting small, fast-breeding feeders
- Very humid tropical setups (they'll survive but may not thrive)
- Those wanting rare, exotic-looking species (these look like big pill bugs)
Care level: Very easy. A. vulgare is the standard against which beginner isopods are measured. If you can't keep these alive, isopod keeping probably isn't for you—they tolerate almost any reasonable conditions and forgive most mistakes.
Value: At £25 for 10, they're priced above common A. vulgare morphs but reasonably for a larger locality. The size difference is noticeable and adds genuine interest. Once established, they breed reliably, making the initial investment stretch further over time.
What to expect: Expect classic pill bugs, just bigger. Expect them to roll into satisfying balls when disturbed. Expect reliable, unfussy isopods that get on with life without demanding constant attention. The larger size makes them more visually impressive than standard A. vulgare, and their Italian origins add mild interest for those who appreciate locality specimens. They won't wow visitors with exotic colours or unusual shapes, but they will consistently do exactly what pill bugs do—clean up organic waste, breed steadily, and roll into balls—just at a more impressive scale.
