Ant colony in 3D

Have you ever wondered how an ant colony is build under ground? We all have seen a simple 2D version - all you need to get one is to place ants in a thin glass container. But how will it look in 3D?
Unfortunately the only way to construct a 3D model involves a total destruction of the colony. It s done by pouring concrete inside the colony, and then when it becomes solid it is possible to digg the resulting structure out of the ground.

In this video 10 ton of concrete were poured in to a colony to create a rather amazing sculpture: