Messor barbarus

Difficulty: Beginner

Queen size: M

Worker size: S to M (strongly polymorphic)

Growth: Medium

Colony size: Large

Climate: Warm

Humidity: Moderate

Activity: Moderate

Winter rest: Recommended

Workers: Small workers plus majors with enlarged heads that crack open seeds.

Development: Slow in the first months, faster once the colony has more workers and warm conditions. Mature colonies can reach several thousand workers.

Origin: Western Mediterranean (Iberian Peninsula, southern France and northwest Africa), in dry grasslands, fields and open ground.

Colony structure: Monogynous (one queen per colony). After the nuptial flight, a young queen starts a new colony on her own and does not need food until her first workers arrive. In Spain these flights usually take place in autumn, a few days after rain.

Good to know: Workers store seeds in special dry chambers called granaries and carry the leftover husks out of the nest to a waste pile.

Read more: our Messor barbarus care guide.

Vibrations: This is the most important point for this species. Messor barbarus is very sensitive to vibrations, which stress the colony and can shorten the queen's lifespan. Place the setup somewhere free of vibrations, such as a separate table or a wall shelf, and avoid moving or touching it more than necessary.

Temperature: Does well at room temperature. Warmer conditions speed up brood development, although colonies can also remain healthy at normal indoor temperatures.

Heating: Optional. Gentle heat on one side of the nest can help a young colony grow. Always leave a cooler area so the ants can choose.

Humidity: Keep the brood area of the nest moderately moist and another area dry for seed storage. Seeds that get too damp can sprout or go mouldy.

Winter rest: Recommended. In nature this species slows down in winter. Many keepers give their colony a cooler rest period from late autumn to early spring, for example in an unheated room. Colonies can be kept active all year, but a winter rest is widely considered good for the queen's long-term health. Feed less during this period, but always keep water available.

Waste: Because they eat seeds, Messor barbarus produce hard droppings. They usually smear these against the glass of the outworld, and in a nest that is too large they will use a whole chamber as a toilet. This becomes very visible as the colony grows. It is completely normal behaviour and nothing to worry about, and it is one more reason not to give the colony a nest that is too big.

Feeding

• Seeds: Seeds are the main food. Young colonies without majors do best with small, soft seeds, such as our Pre-Major Harvester Seed Mix.

• Small portions: Do not give too many seeds at once. Sorting and storing a large pile costs the colony a lot of energy, which slows down growth. Offer a small amount and add more when the stock runs low.

• Insects: Not essential. Wild colonies rarely collect insects, although in our experience offering a small insect now and then does no harm.

• Sugar: Not needed. This species does not take sugar water or sugar jelly.

• Water: Always keep clean water available.

• Hygiene: Remove old husks from the outworld to prevent mould.

Housing

• Founding queen: Leave her in a closed test tube until the first workers arrive. Too much space causes unnecessary stress for the queen.

• First workers: Connect the test tube to a Mini Outworld to give the colony a small foraging area.

• Larger colonies: Once the colony has a large number of workers, move it to the Avalon Ant Nest (Small Chambers version). Avoid a nest that is much too big for the colony.

• Strong jaws: Majors of larger colonies can chew through Ytong, plaster and even acrylic. Check stoppers and nests regularly for damage.

• Escape prevention: Not a strong climber, so small colonies do not need an anti-escape barrier. For larger colonies, apply Fluon to the outworld.