The building is not common coming from the soil, sometimes it could be come from the sky, here an example, it is a structure build in the air, in the top of the tree.
But who could build it, here we can found a nest of ants, or termites houses, or maybe a parrot house, yes a parrot build too this kind of structure for living or for protecting their child.
The build has been coming from this ideas, a glorious ideas which has not develop by humans, the ideas has been development by animals, do not believe me looks around you and told me if I am not have reason.
Enjoy our nature it is a treasure.