Complex sentence: It is a eusocial vespid, which builds its grey paper nest on a structure capable of supporting it, such as a tree, or underground, often using an abandoned mammal hole as a start for the site, which is then enlarged by the workers.
Split into simpler sentences: It is a eusocial vespid which builds its gray paper nest in or on a structure capable of supporting it. Underground it often uses an abandoned mammal hole as a foundation for the site which is then enlarged by the workers.