The Refillable Test Tube Formicarium – Mini Nest Setup is a compact, fully equipped formicarium that works as both a standalone mini nest, an extension to an existing setup or a replacement unit for our Test Tube Array Formicarium and Window Edition systems.

Its design combines the visibility and practicality of a test tube setup with the added control of a refillable water reservoir, specialized nesting area inserts, including light protection and accessories—fully assembled and ready to use. Simply connect to your setup, add water, and you're ready to go. This gives your ants a stable, secure habitat ideal for small growing colonies that have just emerged from the founding stages.

This setup is ideal for keepers who want:

An easy and simple ready-to-use nest for young colonies.
A compatible replacement or expansion tube for our array systems.
A durable, long-term upgrade from traditional bare glass test tube setups.
A quick and easy expansion to any setup with standard vinyl tubing connections.
Precise humidity control for species with specific moisture requirements (like Camponotus vs fire ants)
Species-appropriate substrates for cocoon-spinning or texture-sensitive ants (Formica, Camponotus benefit from textured surfaces)

Each mini formicarium is carefully crafted in-house at Por Amor Art. We precision-print components, hand-select matching tubes, drill watering holes, and apply mineral substrate to inserts. The perlite, fiber plug, and insert are carefully positioned and secured in place by the silicone fitting and cone adapter—creating a complete system that's assembled, tested, and ready to use. Just add water and you're set.

Thriving colonies depend on stable humidity and thermal gradients, species-appropriate nesting space and surface textures, and minimal disturbance—This refillable mini formicarium is engineered around those proven principles.

Please read the info sections to learn all about options and best practices when using this product.

Refillable Test Tube Formicarium - Mini Nest Setup (16×125 mm)

From C$12.00

Quantity

Each mini nest setup is preassembled and includes:

1 × 16×125 mm borosilicate glass test tube with rear watering hole.

1 × Long insert, length 82mm (choose plain plastic or sand-textured—see below).

Clean, sterilized perlite pre-filled in the water reservoir as a moisture buffer for improved water retention and gradual release.

1 × Silicone fitting (1 cm), allows direct connection to array formicarium modules or cone adapters.

1 × Cone adapter for vinyl tubing, choose 9.5 mm (3/8") or 12.7 mm (1/2”).

1 × Long light-protection jacket with attached rear elevating ring.

1 × Tall black plastic ring for stability on flat surfaces.

The rings raise the tube to match connection port height and provide clearance for heat cables to pass underneath, while the cone adapter allows easy connection to outworlds or other formicaria with standard vinyl tubing—no custom fittings required.
Species requiring textured surfaces for proper larval development and cocoon spinning (Camponotus, Formica) benefit from sand-textured inserts, while species that develop well without specialized spinning substrates (Lasius, Tetramorium) perform equally well on plain plastic inserts.

Plain plastic: Features multiple grooves across the floor for cocoon spinning, with micro-textured surfaces from 3D printing that provide better grip compared to bare glass. Cost-friendly option suitable for most species.

Sand-textured: Treated with mineral mortar paste to create a rugged substrate surface. Offers enhanced grip, better moisture distribution, reduced flooding through water absorption, and a more natural environment that promotes faster brood development and higher worker counts.
9.5 mm (3/8"): Best for smaller colonies, species that prefer narrow passages, or connecting to small outworlds.

12.7 mm (1/2"): Allows greater traffic flow, easier for large workers or mixed-size species.

Humidity consideration: Smaller diameter tubing provides slightly less airflow and helps maintain higher humidity in the nesting area, while larger tubing increases ventilation and slightly reduces humidity levels. Consider your species' moisture preferences when choosing tube size.
Refilling Technique:

Add distilled water slowly with a syringe or pipette - water travels gradually toward the fiber plug, so filling too fast prevents proper control. Watch the fiber plug change from dry to moist.

How much to add depends on your species: For low-humidity species like Camponotus, stop when the plug is barely damp and the perlite is only slightly moist.

For high-humidity species like fire ants, you can wet the plug more thoroughly and saturate more of the perlite - but stop before water appears under the insert area, which signals overflow.

Start conservative and adjust based on your colony's needs. If you accidentally add too much, use a syringe to suck excess water back out through the watering hole. Using distilled water is preferred as it prevents mineral buildup and bacterial growth that can harm your colony.

Understanding Traditional vs. Refillable Designs:

Compared to refillable systems, traditional sealed test tubes can hold more water but create problems: air bubbles trapped in the water cavity can expand from temperature changes causing flooding, cotton plugs can shift backward as water evaporates, and ants can dig into the cotton and reach the water directly, often resulting in messy floods. Our rear watering hole equalizes back pressure and creates a stable, controllable humidity buffer, eliminating these issues - which is why we include perlite to maximize water retention through capillarity.

Precise Humidity Control:

Different ant species have varying humidity preferences, this system lets you control moisture levels by adjusting water saturation in the absorption chamber. More saturated perlite creates higher nesting humidity, while drier perlite provides lower humidity for species requiring drier conditions.

Long-term Maintenance:

Unlike traditional setups where you're limited to the initial water supply, this system allows continuous monitoring and refilling as needed. Colonies may vacate for several reasons: natural outgrowth as they expand (typically 6-12 months depending on species), waste buildup from extended use, or mold development - which often occurs when very small colonies are given too much space and the nest is over-watered.

Once ants have vacated, replace the fiber plug and refresh perlite for reuse with future colonies. Visit the insert cleaning guide to learn how to make the most out of your used inserts.
Fits all Por Amor Art – Test Tube Array Formicarium systems, including the Window Edition.

Works with our 16×150 mm test tube accessories—same diameter for full compatibility.

Using the included cone adapter, you can connect directly to outworlds or any other formicaria with standard vinyl tubing ports.

For best results, expand gradually—if using an array system, keep unused test tube ports closed and only open or connect one at a time. This mimics natural nest growth, keeps the active space tight and clean, and encourages the colony to move in more quickly.