Nature Communications 2: Article number: 397 (2011); Published: 19 July 2011; Updated: 5 February 2013.

This Article contains typographical errors in Equations (6) and (7), where terms were inadvertently left out. These errors were not present in the analysed model itself, so did not affect the results.

Equation (6) is missing the term (n–1)dw, representing worker mortality in colonies of size n, and should read:

Equation (7) should read:

In addition, some of the entries in Supplementary Table S1, lines 4 and 5, were inadvertently exchanged. The correct version of the Table appears below.