Collective constructions are marvels of complexity, composed of networks of tunnels and chambers. However, it is difficult to study subterranean nests without using invasive techniques because the nests are built within pieces of wood and/or in the soil. Using computerized tomography scans and medical imaging software (OsiriX), we were able to observe nest creation, constructions, and architecture of two subterranean termite species. We monitor the nests' growth in three dimensions built by two Reticulitermes species: R. grassei, a species native to Europe, and R. flavipes, an invasive species introduced from North America, over a several month period. Doing so, we wanted to know whether the construction of the nest could participate to the invasive success of R. flavipes. Although the two species displayed some similarities (i.e., nest creation, chamber size, and levels of wood consumption), only R. flavipes built interior structures. Some of these structures changed over time and thus might play a role in the trade-off between wood consumption, colony protection, and environmental homeostasis.