A living door inside a tropical nest

Colobopsis leonardi is a wood-nesting ant from China and Southeast Asia whose appearance is closely tied to colony defence. Its large soldiers are especially distinctive. The front of a soldier’s head is flattened, hard and roughly textured, resembling a piece of cork or tree bark. This shape is not merely ornamental: it functions as a specialised barrier at the entrance to the nest.

The species offers more than the usual opportunity to watch a colony grow. It reveals a clear division of defensive roles. Workers maintain the nest, tend the brood and collect food, while soldiers can turn their own bodies into movable plugs that protect the family behind them.

Phragmosis: defence built into the head

In the wild, Colobopsis leonardi inhabits hollow branches with narrow openings leading to protected internal chambers. When danger approaches, a soldier positions itself inside an entrance and seals it with the flat front of its head. This defensive method is known as phragmosis.

The exposed surface forms a hard, rough plug that gives a predator little to grasp. The queen, brood and workers remain behind this living barrier. Similar behaviour may be observed at suitably sized nest entrances or connecting tubes in a formicarium. The ants should not be repeatedly disturbed simply to trigger the response; their defensive organisation is better observed during normal colony activity.

Why older sources say Camponotus

Older publications and keeper discussions may list the species as Camponotus leonardi. It was historically classified with Camponotus, while Colobopsis was later recognised as a separate genus. Several related traits remain apparent, including wood-associated nesting and the use of carbohydrate-rich food. The highly specialised soldier head is the feature that most immediately distinguishes this colony.

Creating a suitable moisture gradient

Its association with wooden nests is important when planning captive housing. Persistently wet conditions are unsuitable, yet complete dryness can endanger the brood. The goal is therefore not uniform moisture throughout the nest but a controlled gradient that gives the ants a choice between drier and more humid chambers.

A partially plaster-based formicarium can provide this arrangement. A hygroscopic G23 plaster section retains moisture, while PETG compartments create additional zones with different conditions. The colony can place cocoons in a drier area and move larvae closer to the moistened section. A conventional plaster nest may also be used when the amount of water added is carefully controlled.

When selecting and preparing the enclosure, consider:

• whether it can maintain a gradual moisture gradient;
• whether residential chambers can be kept free from constant saturation;
• whether entrances and tube connections are secured against escape;
• whether passages provide enough room for the large soldiers;
• whether the brood can be inspected without frequently disturbing the nest.

Formicaria using nano-sponges are not recommended for this species in the supplied husbandry information. No nest material removes the need for observation: hydration should be adjusted gradually according to chamber conditions and the colony’s placement of its brood.

Temperature and feeding

The stated arena temperature range is 25–28°C. Stable conditions are preferable to abrupt changes, so the actual temperature around the enclosure should be monitored, particularly when local heating is used.

Honey or sugar syrup supplies the carbohydrate portion of the diet. Animal protein is required for brood development and the production of new soldiers. The listed feeder insects are crushed Turkestan cockroaches and small crickets. Portions should reflect colony size and current feeding activity, and uneaten protein food should be removed before it soils the arena.

Who should keep this species?

Colobopsis leonardi is suited to a keeper with basic experience in managing nest humidity. The central challenge is maintaining balance: the wood-associated ants should not remain in excessive dampness, while larvae must retain access to a humid zone. In a properly arranged formicarium, the colony can distribute cocoons and larvae between the available microclimates.

Questions and answers

Why does Camponotus leonardi appear in older references?
That is the species’ former taxonomic combination. It was long associated with Camponotus, so the older name remains common in archived publications and discussions, while the current name used here is Colobopsis leonardi.

How does a soldier close the nest?
The soldier occupies a narrow passage and presents the flat, hard front of its head to the outside. Its body becomes a living plug protecting the queen, brood and internal chambers.

Is the species suitable for a first colony?
Some prior experience with moisture gradients is advisable. The keeper must avoid both prolonged wetness and complete drying, maintain the stated 25–28°C range, and provide both carbohydrate food and animal protein.