Table 1.

Summary of experiments

Experiment	Experimental manipulation	Experimental conditions	Results
1	Nurse-age workers were caged on a broodless honey comb inside the hive	Hive: +	Behavior: caged bees showed activity rhythms similar to those of foragers, nurses were active around the clock.
		Brood: −
		Queen: +?	Clock gene expression: strong oscillations in caged bees and foragers but not in nurses.
		Comb: +
		IL: LD
2	Nurses were caged on a brood-containing or broodless comb outside the hive	Hive: −	Behavior: nurses with brood were active around the clock; nurses without brood were more active during the day.
		Brood: +/−
		Queen: −	Clock gene expression: strong oscillations in nurses caged without brood and in foragers, attenuated oscillations in nurses caged on a comb with brood.
		Comb: +
		IL: LD
3	Nurses were transferred to individual cages in constant lab environment	Hive: −	Nurses showed circadian rhythms in locomotor activity shortly after transfer to the lab.
		Brood: −
		Queen: −
		Comb: −
		IL: entrainment in LD, monitoring in DD
4	A group of nurses were removed from the hive to a cage for 16 h and then sampled every 4 h	Hive: −	Strong oscillations in foragers, weaker but significant oscillations in nurses that were transferred to a cage, attenuated oscillations in nurses.
		Brood: −
		Queen: −
		Comb: +
		IL: LD
5	A group of nurses were removed from the hive to a cage for 8 h and then sampled every 4 h	Hive: −	Strong oscillations in foragers, attenuated oscillations in nurses and in nurses that were transferred to a cage.
		Brood: −
		Queen: −
		Comb: +
		IL: LD

IL, Illumination regime; LD, 12 h light/dark; DD, constant dim red light.