Panel A: a worker bee in a modified Eppendorf tube that we use in tests of survival capacity in hyperoxia. The lid has holes for feeding and air exchange. The end of the tube is cut open and sealed with cotton to absorb faeces. Panel B: survival data for nurse bees (caregivers) scored as poor learners (green line/bar, learning score = 0 to 3, n = 50) and as good learners (black line/bar, score = 5, n = 85). Nurse bees were collected from four single-cohort colonies; tested over four weeks as independent replicates. Replicate did not influence the proportion of bees surviving, but learning ability had a significant effect .