General information

Common name

Harvester ant

Binomial nomenclature
Messor barbarus

Family: Formicidae
Subfamily: Myrmicinae
Genus: Messor
Species: Messor barbarus

Mostly around the Mediterranean Basin and North Africa. See

Gardens, parks and forests.

Deep soil nests.

Polymorphic, but without real distinctive castes.
Workers: 3 – 9 mm
“Majors”: 9 – 14 mm
Queen: 14 – 18 mm

Keeping and care

Easy. Suitable for beginners and intermediates, but shouldn’t be disturbed too often.

Behavior and description
No sting, but larger workers can bite. They collect, store and consume seeds and form trails. Sensitive to vibrations. The “majors” have massive heads and jaws for chewing seeds.

Colony type
Monogynous. Independent founding. Colonies can become very large. When the colony reaches a decent size, they will produce larger workers.

Queen capture
Capture unwinged queens after nuptial flight in autumn. Digging out a colony is not recommended because of the monogynous nature of the colony, making it almost impossible to find the queen. Will start laying eggs after winter.

Nuptial flight
September – October

Test tube setup for small colonies, ytong nests for large colonies, with a foraging area attached. Plaster and sand nests are also possible. Please note that they can dig through ytong and plaster. It is best to build the nest inside a container (like a small aquarium) to prevent outbreaks. A concrete nest is also possible, because they can’t dig through concrete, but it will be heavy.

Nest conditions
Some humidity is required, but not too much. They live in dry areas. Best is to offer a nest where one part has some humidity and one part has low humidity, so they can choose. Can be kept at room temperature, but they prefer higher temperatures, around 25 – 30 degrees Celcius (77 – 86 degrees Fahrenheit), so a heat mat is recommended. Covering the nest to make it dark is recommended to reduce stress. The nest is often covered with red foil, but I’m not convinced they can’t see through it. As a granivorous species, they also need some room to store seeds. They are very sensitive to vibrations and shocks and are easily stressed by too much disturbance.

Escape prevention
Fluon, talcum powder. Paraffin oil not recommended because they drown easily. Not good climbers so they won’t escape easily. Is able to dig through ytong.

Not obligatory, but around six weeks of dormancy at 10 – 15 degrees Celsius (50 – 59 degrees Fahrenheit) is recommended. During dormancy their metabolism is strongly minimized, so feeding is not required, but moist is. After dormancy, increase the temperature slowly to desired temperature to avoid intoxication by built-up toxics due to the reduced metabolism.

They are granivorous, so they mainly require seeds (dandelion seed, grass seed, bird seed). Complement with honeydew surrogate, sugar water and insects (e.g. fruit flies, crickets, Blaptica dubia). Be careful with liquid food sources, because they drown easily. Provide on cotton to prevent drowning.


Messor barbarus
Messor barbarus natural nest entrance – Photo by Jebulon
Messor barbarus
Dandelion seeds harvested by a young colony in a test tube

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