Carebara castanea

This marauder ant is for keepers chasing sheer scale: given time and steady care, a single colony can swell into an enormous, dense foraging force, building busy trails that few other species rival. It is active around the clock and comes from the humid forests of Sumatra, so it leans entirely on dependable heat and high humidity. The challenge is logistical as much as anything, since housing and feeding a population this size is no small commitment. Rated Pro, it is meant for an expert ready to scale up the setup as the colony grows.

A marauder that leans hard on insect protein to feed its vast and hungry brood, with a constant sugar source to keep the workers moving. Bring plenty of prey and never let the sweet supply run dry.

★★★ readily · ★★ moderately · ★ occasionally · ✗ not eaten

Start this species in a compact, humid setup with no loose joints, as the smallest minors escape through pinholes. Step it up through progressively larger moisture-holding nests as the colony marches toward the hundreds of thousands, keeping every connection fine and sealed. Maintain an arena barrier of fluon (PTFE), a fine oil line, or talc and water, and inspect it regularly. ANTonTOP formicaria and starter kits provide humid, well-sealed nests with matched arenas that scale with a colony this size.

Tracking its humid Sumatran origin, keep the nest at 25-28 °C and the arena at 25-29 °C, with nest humidity high at 70-85% and the arena at 50-70%. Heat one side for a gradient so the colony can pick its comfort zone, and keep the nest dependably moist. With no winter rest for this tropical species, hold conditions steady and feed throughout the year.

Founding is slow, then the pace ramps up steeply once workers appear, the colony able to reach up to 500,000 workers. It arrives as a fertilised queen with workers and brood, already through the hardest early stage.

• Carebara show one of the sharpest size contrasts of any ants, tiny minors set against a queen many times their length.
• Marauder ants in this genus raid in dense columns, overwhelming and dismembering prey that would defeat a lone forager.
• Their smallest workers can be minute enough to slip through the tiniest gaps, which is why keepers seal connections so carefully.
• The marauder group was once placed in the genus Pheidologeton before being folded into Carebara.

Is Carebara castanea good for beginners?

No, it is rated Pro and demands steady tropical care, so it suits experienced keepers.

Does Carebara castanea need a winter rest?

No, this tropical marauder takes no hibernation; keep it warm and humid year-round.

Does it sting?

Yes, its sting can give moderate pain, so handle with care.

How many workers can a Carebara castanea colony reach?

Up to 500,000 workers.

How large is the queen?

The queen measures 18-24 mm.

How quickly does it grow?

Slow during founding, then steeply once the colony is established.

What does it eat?

Insect protein for the brood plus a constant sugar source.

Will it arrive alive?

Colonies ship with a queen, workers and brood plus a heat or cool pack, dispatched within 24 hours with tracking.

Escape prevention. Coat the inner rim of every open arena with fluon (PTFE), or use talc-and-water or an oil barrier as a backup, and keep a tight, fine-mesh lid on top. Check the barrier regularly, since dust, condensation and feeding debris break a fluon line over time. Keep tubing connectors tight and seal any gaps in the nest.

Keeping reminders. Always offer fresh water and never let the nest dry out completely. Give carbohydrates continuously and protein a few times a week, and remove uneaten insect prey within 24 hours before it moulds. Keep the formicarium out of direct sunlight and away from constant vibration, which stresses a young colony. A water-filled test tube plugged with cotton makes an ideal spare incubator whenever you need one.

Before you buy – do not rehouse too early. Have a test-tube setup or a small formicarium with an outworld and a working barrier ready before your colony arrives. A founding colony grows slowly at first, which is normal. Moving a small colony into a large nest too soon invites mould, mites and stress, and the workers die off one by one. Keep the colony in its open test tube on the arena, plug the nest entrance with cotton, and open up the next chambers only once the colony fills roughly 10-15% of the space.

What we ship. Every colony ships with a live-arrival guarantee, backed by our 24h unboxing-video guarantee: if the queen does not arrive alive, we reship free. Parcels travel with DHL, InPost (PL) or EMS, with a heat or cold pack to suit the season, packed discreetly and securely. We ship across the EU and worldwide, with free shipping over the Europe threshold.