Direct behavioral observations uncover shift work on honey bee Apis mellifera

Division of labor is one of the key features of societies, from humans to insects. Task specialization increases overall efficiency and performance and is considered the base for the success of social systems. It has recently been shown that genetic differences between honey bee foragers have a impactful effect on foraging time. Since it is well established that honey bees use their circadian clock to tell time of day, changes to the circadian machinery may influence timing of behaviors in foragers. Here, we present novel behavioral observations demonstrating shift work for foraging and fanning behaviors in honey bee foragers throughout several days. Furthermore, using circadian light sensitivity assays, we tested whether individual differences in light sensitivity of the circadian clock play an important role on shift work preference. Our findings reveal that light sensitivity of the circadian clock influences foraging and fanning in honey bee foragers. Future studies aim to elucidate the mechanisms of shift work and light signaling to the circadian clock as well as its functional and evolutionary role.