The colony foundation and development, and pattern of young and established nests of Odontotermes obesus and O. wallonensis were investigated. Swarming of alates of both the species occurred during pre-monsoon (April/May) and continued throughout the wet months. After pairing, alates of both the species selected sites in crevices of the soil or in loose soil for the foundation of a colony. The active construction of the mound was observed during the cool hours of the day in rainy months.
The young nests of O. obesus was conical-shaped with one or more conical turrets, whereas it was dome-shaped with one or two domes like turrets in O. wallonensis. In young colonies, the fungus combs were aggregated in the central cavity and the royal chamber was situated beneath usually at the centre. The established nests of both the species were extended by addition of vaults, galleries, runways, etc. The mound nest was extended in vertical direction in O. obesus, whereas it was extended horizontally in O. wallonensis.
