Duration of development of queen- and worker-laid eggs. *100% = total number of eggs that hatched successfully. N = 160, 114 and 204 in the three trials. The time course of hatching differed between queen- and worker-laid eggs in trials 1 and 3 (Gehan’s generalized Wilcoxon test, P < 0.001 in both cases), but not in trial 2 (P = 0.576).