Following Molet et al. (2007), we calculated
thorax volume as a mean of two volumes: lateral
area multiplied by dorsal width and dorsal area
multiplied by lateral height. To assess differences
between large and small individuals, we computed
growth rules between several traits (Peeters &
Molet 2010a). Thorax volume was also calculated
for queens (n = 12) to describe size dimorphism
relative to workers, as well as other species; such
measures are useful for comparative studies of
colony-founding ability in ants.