Stenamma diecki is a small ant with a widespread distribution. Systematic plot excavations in two locations have allowed us to collect data on a large number of S. diecki nests in order to examine seasonal and spatial differences in nest demography and allocation decisions within this species. Populations of this species from New York and Vermont nest in cavities far more commonly than has been reported, and thus we could compare our results with data on this species and with patterns of demography and reproduction for two other well-studied cavity-dwelling ants. We found nests were monogynous at all locations, but showed considerable variation in mean queen number and mean worker number. Most nests did not produce any males or reproductive females in a season, and this pattern was also site specific. Sexual and reproductive allocation was similar for all sites tested. Finally, demographic patterns within a site over 3 seasons are consistent with those predicted by seasonal polydomy.