Messor structor

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, dark 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 become large.

Origin: Central, southern and eastern Europe, in dry grasslands, fields and other warm, open places.

Colony structure: Colonies can have one queen or several queens together. Young queens start a colony after the nuptial flight and do not need food until the first workers arrive. That is why we offer this species with one or two queens.

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

Read more: our Messor structor care guide.

Vibrations: The most important point for this species. Messor structor is very sensitive to vibrations, which stress the colony. 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.

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. Give the colony a cooler rest period from late autumn to early spring, for example in an unheated room. Feed less during this period, but always keep water available.

Waste: Because they eat seeds, harvester ants produce hard droppings. They often smear these against the glass, and in a nest that is too large they use a whole chamber as a toilet. This is completely normal and 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. Offer a small amount and add more when the stock runs low.

• Insects: Not essential, but a small insect now and then does no harm.

• Sugar: Not needed. Harvester ants do 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.

• 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.