Ant Farm Outworld Size | Why the Foraging Area Matters Less Than You Think
How big should your ant farm outworld be? It is one of the questions we hear most, and the honest answer surprises most new keepers: much smaller than you think. We have kept ants since 1997, in the wild and in our own setups, and we have seen the same thing again and again. When food is close to the nest, the ants we keep make short trips and spend their time at home.
Here is why the foraging area matters far less than the nest, what science says about foraging, and when a bigger outworld still makes sense.
What Is a Foraging Area?
The foraging area, or outworld, is the open part of an ant farm connected to the nest. It is where your ants find food and water, drop waste and explore. On our pre-formed nests the outworld is the feeding area: the colony lives, rests and raises its brood inside the nest, and only the foragers come out to collect food.
Why Do Ants Forage at All?
In nature, ants forage because they have to. Food is scattered, unpredictable and shared with competitors, so a colony must send workers out to search for it. Some species travel remarkable distances:
Red harvester ants (Pogonomyrmex barbatus) can have foraging trails extending around 60 metres from the nest.
Black harvester ants (Veromessor pergandei) of the American deserts march out in a single column of 3 to more than 40 m, then fan out to search. Their foraging site can be 70 m or more from the nest.
European harvester ants (Messor barbarus) follow trunk trails of up to 30 m. In a field study in southern France, their trails reached 25 m from the nest.
Red wood ants (Formica rufa) build foraging trails that can stretch to around 100 m.
Leafcutter ants (Atta cephalotes) build trunk trails up to about 100 m long, and some leafcutter colonies dig underground foraging tunnels of around 70 m.
Saharan desert ants (Cataglyphis fortis) hold the record. They forage alone, more than 350 m out into the salt pans, and one forager walked 1.1 km on a single homeward run and still found its nest.
Camponotus vagus, a large carpenter ant, usually forages up to 30 m in nature.
Predatory ants such as Harpegnathos venator and trap-jaw ants hunt up to 7 to 10 m from home.
To put that into perspective, a 6 mm worker walking 60 m covers 10,000 times its own body length. For a person, that would be a trek of roughly 17 km. Every metre costs energy and brings risks from predators, heat and getting lost. Ants only make those journeys because they need to.
Trail length is not the same as the size of the foraging area. Two 60 m trails running in opposite directions put their far ends about 120 m apart, yet no single ant has travelled more than 60 m from the nest.
What Happens When Food Is Close to the Nest?
This is the key point, and we have tested it many times over nearly three decades, both in nature and in our own setups. In our experience, when ants are given food close to the nest, they do not travel further than they need to.
We still feed several Formica rufa colonies here in the UK, a species listed as Near Threatened on the IUCN Red List. Closer to home we have also checked Tetramorium caespitum (the pavement ant), Lasius niger and Lasius flavus, which spends around 90% of its time underground and is not a big forager at all. In these colonies, food near the nest meant short trips.
Our Messor barbarus observations cover 11 years, including a massive wild colony in Europe that we feed during our annual summer trip searching for new species. In one established wild colony, the workers collected the seeds we supplied and then showed no observed foraging for at least five days.
In colonies we observed, other species behaved in the same way. A massive Camponotus vagus colony, which normally forages up to 30 m, did not go out to search again for a month after we gave it enough food next to the nest to fill its stores.
In colonies we observed, predators did the same. A small wild colony of Harpegnathos venator, about 30 workers, carried a pre-killed locust placed close by into the nest and fed on it for a week without going out to hunt again. The trap-jaw ant colonies we observed behaved the same way.
Separately, research on a different harvester ant, Pogonomyrmex barbatus in the United States, shows how colonies regulate foraging. At Stanford University, Professor Deborah Gordon found that these colonies decide how many foragers to send out by how quickly foragers come back with food. When food is found fast, more ants head out; when foragers return empty-handed, foraging slows and can stop altogether. Researchers compared it to the way the internet manages traffic and nicknamed it the "Anternet".
What Do Ants Do All Day?
A colony's main job is raising the next generation, over and over again. In an established colony, the queen's job is laying eggs, so she stays inside the nest and never goes out to forage. Most workers spend their time inside too, caring for eggs, larvae and pupae, cleaning and storing food.
In fact, not every worker is busy at all. Researchers at the University of Arizona found that around 40% of the workers in Temnothorax colonies are mostly inactive. When the busiest workers were removed, these so-called lazy ants stepped in and replaced them within a week, so they act as a reserve team waiting for work.
Army Ants | The Exception
Army ants are the best-known exception. They have no permanent nest: the workers link their bodies together to form a living shelter called a bivouac. In Eciton army ants, colonies alternate between two phases. During the nomadic phase, about two weeks while the larvae grow, the colony relocates to a new bivouac almost every night. During the stationary phase, about three weeks while the eggs and pupae develop, it stays in one place. Their movements follow the development of the brood, not simply the search for food. African driver ants move far too: on Mount Kenya, colonies of Dorylus molestus shift their whole nest an average of about 93 m in a straight line each time they emigrate. For the species kept at home, the nest is the centre of life.
Proof | From 12 to More Than 700 Workers in the Antie
Our favourite example comes from our own collection. We raised a Camponotus nicobarensis colony in the Antie ant farm, with its small outworld, from a queen and 12 workers to a queen and more than 700 workers in almost two years. The small foraging area never held them back, because the nest gave them everything they needed.
The Antie's small outworld measures 90 × 95 × 95 mm, and we have used this size successfully for established colonies of up to 500 workers.
So Why Choose a Bigger Outworld?
If ants are happy with a small outworld, why do we make bigger ones? Simply because people love watching their ants forage. A larger arena is a display choice: it gives you more room to decorate, more space to watch the foragers at work and a more natural-looking setup. We love them for exactly that reason.
Our outworlds come in three sizes: the Small Ant Farm Arena Outworld Set, the Ant Farm Arena Outworld Medium Set and the Large Arena Outworld Formicarium. If you would like a medium outworld from day one, the Antie Plus comes with one fitted.
The Tubing Method | Let Your Ants Travel
For display setups, the outworld can sit away from the nest on a coil of PVC Clear Tubing 8x11mm. Watching a line of foragers travel along the tube is one of the most rewarding sights in ant keeping. Extend the tubing gradually so the colony can adjust:
Start with no more than 25 cm.
After a month, extend it to 50 cm.
The month after, 75 cm.
Then 1 m, adding length month by month up to 5 m.
Try It at Home | A Simple STEM Ant Experiment
This is a brilliant experiment for children, classrooms and curious adults alike, from nursery to university.
Use an established colony that has settled in, and follow its normal feeding schedule.
Place a tiny drop of protein jelly or organic honey on a small piece of tin foil right next to the outworld entrance.
At the next feed, place the same amount at the far end of the outworld.
Each time, note how long the ants take to discover the food, how long each trip takes and how many foragers come out.
Record your results in a table, compare the two, and remove any leftovers after two days.
What do your results show? Repeat the test a few times and see whether a pattern appears. For printable worksheets and feeding schedules, use our free ant farm science resources for schools and parents.
The Bottom Line
The size of the foraging area matters far less than most people think. Ants forage because they have to, and in our experience, when food is close they stay home and raise the next generation. The nest is the most important part of any setup, so put your money there first, then choose an outworld for the joy of watching.
For a complete start, our Lucas kit with Lasius niger and our Angie kit with Messor barbarus both include a nest with a built-in humidity and temperature meter. Already have ants? The A7 Plus is the nest we recommend.
Frequently Asked Questions
Does the size of an ant farm outworld matter?
Not as much as most people think. In our experience, when food is placed close to the nest, ants make short trips and spend most of their time inside raising brood. A bigger outworld is mainly a display choice for your viewing pleasure.
How big is the Antie's outworld?
It measures 90 × 95 × 95 mm. We have used this size successfully for established colonies of up to 500 workers.
How far do ants forage in the wild?
It depends on the species. Red harvester ant trails can extend around 60 m from the nest, and Messor barbarus trunk trails reach up to 30 m. Red wood ant and leafcutter trails can reach around 100 m, and Saharan desert ants have been recorded foraging more than 350 m from the nest. Many smaller species stay within a few metres of home.
Will my ants be bored in a small outworld?
No. Ants do not forage for fun. In our experience, when their needs are met they stay in the nest and care for the next generation.
Does the queen ever come out into the outworld?
In an established colony, no. The queen stays inside the nest laying eggs while the workers bring the food to her.
Can I connect a bigger outworld later?
Yes. All Best Ants UK ant farms are compatible and connect to one another, so you can extend your colony's space through the nest, the outworld or both.
How do I add tubing between the nest and the outworld?
Use PVC clear tubing 8x11 mm and extend it gradually: no more than 25 cm at first, then 50 cm after a month, 75 cm the month after, then 1 m, month by month up to 5 m.
Where should I put food in the outworld?
In the outworld only, on a feeding dish or a small piece of tin foil, and remove any leftovers after two days. For harvester ants, never put seeds directly on the substrate.
Do all ants behave like this?
Not all. Army ants are the best-known exception: they have no permanent nest and relocate frequently during their nomadic phases, with their movements following the development of their brood.
