This is a termite nest. Almost all of these termite nests are in tree trunks. I found this termite nest in an oil palm tree. We don't know how long it takes these termites to build a nest as grand as this. Of course this is not an easy job, it needs solid cooperation.
These nests are made of earth. The ground is a bit muddy, constructed in such a way by the architect in the field. When we investigate this termite nest, it does not contain cement or similar adhesives. However, this building is not careless, it can be seen from the strength of the building. Well, amazing isn't it.