The construction pattern and occupancy of Ectatomma vizottoi was described, during November 2004-August 2006 period, in Dourados, state of Mato Grosso do Sul by excavation of eight nests. The entrance openings, or exit, have an ellipsoid shape and lead to a wide tunnel, similar to a hall, which is connected to other deeper chambers in the nest. The nests reach up to 360 cm deep and contain three to ten chambers. Nests are constructed independently of plants and roots presence, and the soil of the tunnels and chambers are compacted, with specific compartments for colony deposit of detritus. The increase of the ant density led to an increase in nest depth and number of chambers, maintaining an average nest volume, which indicates a standard size for nest chambers.
Ectatomminae; population; structure of nests
