Ants are proverbially associated with industry, so it is not surprising that they build their own homes, which are located in ant colonies. Ant-hills are generally built and maintained by the most hardworking of the ants in the colony, known as the worker ants. Building an ant-hill is a collective effort which involves a massive group of worker ants. Ant-hills are made up of combination of sand, pine needles, earth and clay, which are piled up in the form of a crude hill in front of an ant colony after it has been excavated. The worker ants then carry a heap of mud and vegetation in their mandibles. The mandible is a jaw-like appendage near the ant's mouth. The worker ants then deposit all these materials at the top of the ant-hill and at the exit of the ant-hill to prevent it from sliding back into the colony.