Empty storage combs in honeybee nests regulated the nectar-harvesting activities of occupant bees. Increased honey storage stimulated by the presence of more empty comb was associated with more intense nectar-harvesting behaviour both in and away from the hive. Foragers from hives with more comb were less likely to collect food of lower sugar concentration; however, when they did collect it, they were more likely to perform recruitment dances upon their return to the hive. Colonies with more empty comb stored more honey during major nectar flows but less during minor flows. Among colonies supplied with similar amounts of comb, those that stored more honey during major nectar flows stored less during minor ones.