Lasius illyricus

This is a workhorse of a colony from Croatia and the wider Balkans and Mediterranean. Founded claustrally by a single queen, it builds into a populous nest, so once it gets going you get fast, visible activity across the arena. The bite is mild and there is no sting, which keeps handling stress low even as the population climbs. Rated Intermediate, it rewards a keeper who can manage a mandatory winter rest and a steadily growing colony, rather than an absolute first-timer.

An omnivore that raises its brood on insect prey while the workers run largely on honeydew gathered from aphids. Keep a sugar source available at all times and offer protein two to three times a week to drive growth.

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

Start a young colony in a small test tube or starter setup, then move it into a formicarium once the workers fill the space. An aerated concrete, acrylic, or hybrid nest with a connected arena suits this warm-summer Balkan ant; keep it moderately moist with a drier foraging side and one damp brood corner. As numbers climb, step up nest and arena size. Coat the rim with fluon (PTFE), oil, or talc and water. ANTonTOP starter kits pair a sized nest with arena, feeders and barrier so you are ready from day one.

Suit it to a warm Balkan summer: nest at 20-26 °C and arena at 22-32 °C, with humidity at 55-70% in the nest and 40-60% in the arena. Heat from one side only so the colony can pick its comfort zone along a gradient. Wintering is mandatory, a cool rest at 5-10 °C for 4 months that keeps the colony healthy and laying well the next season.

Like most Lasius it starts slowly in the first season, then accelerates sharply once the worker force is established, climbing toward 10000-30000 workers over time. From one founding queen the colony eventually becomes a fast, busy nest. You receive a queen with workers and brood, ready to build into a full formicarium.

• Lasius queens are exceptionally long-lived for such small ants, with the genus holding some of the longest insect lifespan records on file.
• Lasius success across Europe rests heavily on tending aphids for honeydew, both at the surface and among plant roots underground.
• This species belongs to the dark, soil-nesting group of Lasius native to the Balkans and the wider Mediterranean.
• New colonies are founded by a single queen sealing herself away to raise the first workers alone before the population takes off.

Is Lasius illyricus good for beginners?

It is rated Intermediate, so it suits a keeper with a little experience, mainly because of the mandatory 4-month winter rest.

Does Lasius illyricus need a winter rest?

Yes. A hibernation at 5-10 °C for 4 months is mandatory for long-term health.

Does the Balkan black ant sting or bite?

It has a mild bite and no sting.

How big does the colony get?

It builds large nests of 10000-30000 workers.

How big is the queen?

The queen is about 7 mm; workers are 2.5-4 mm.

How fast does Lasius illyricus grow?

Slow at first, then fast once the first workers mature and population builds.

What does it eat?

Sugar water or nectar for energy plus insects like crickets and flies for protein; it does not take seeds.

How is it shipped and will it arrive alive?

It ships as a queen with workers and brood, with a heat or cool pack, sent within 24 hours with tracking so it travels fast and safe.

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.