Ants are remarkable not only for their social organization but also for the physical structures that help them survive, communicate, and adapt to a wide range of environments. From the architecture of their nests to the specialized design of their bodies, every structural detail plays a part in the success of the colony. The Essential Ant Vocabulary – Part 3 introduces key terms related to nest structures, exoskeletons, and ant body parts, offering a clear and approachable foundation for understanding how form and function come together in ant biology. While not exhaustive, this overview provides the essential building blocks for exploring ant anatomy and construction in more detail. If you’d like a bit more context, this article naturally follows on from Parts 1 in . Parts 2, which will be linked for further reading.

An ant nest is the internal living structure of a colony. It includes chambers and tunnels that house the queen, brood (eggs, larvae, pupae), and food reserves. Nests can be underground, on a tree, inside wood, rocks, plants, or even a single acorn.

Strictly speaking, an anthill is the visible mound of soil or sand built above some nests. In common usage, however, “anthill” often refers to the entire nest system, including both underground and surface structures.

Ants do not have shells. Instead, they possess an exoskeleton, an external skeleton made of chitin. This structure provides protection, muscle attachment, and prevents water loss.

The integument is the complete outer covering of the ant’s body. It includes the exoskeleton and associated layers, forming the interface between the insect and its environment.

Chitin is a structural protein produced by ants and other arthropods. It forms the main component of the exoskeleton, unlike shells, which are calcium-based and external to the animal’s body.

The gaster is the posterior part of an ant’s body, commonly called the abdomen in non-specialist language. In entomology, “gaster” is preferred because it excludes the petiole segments.

Ants have compound eyes composed of numerous visual units called ommatidia. These eyes are well adapted to detecting movement rather than forming detailed images.

Ocelli are simple eyes located on the top of the head. They detect light intensity and orientation and are mainly found in winged ants such as queens and males.

The petiole is the narrow waist segment (or segments) connecting the thorax to the gaster. Its shape is often used to identify ant species.

Mandibles are the ant’s powerful jaws, used for carrying food, excavating soil, defending the colony, and manipulating brood.