It is well documented that sleep has a supportive effect on memory consolidation in animals. In fact, research has shown that specific types of memory consolidation, in humans, are linked to different stages of sleep. Conversely, there is also evidence that certain kinds of memory consolidation may be independent of sleep.

In a paper published in the Journal of Experimental Biology (215, 3981–3988; 2012) , Randolf Menzel and his colleagues at the Free University of Berlin (Germany) study honey bees to explore whether learning during navigation leads to sleep-dependent memory consolidation. Menzel and his team first characterized how honey bees find their way home after being captured and released in unfamiliar territory (forced navigation task). Select bees were outfitted with radio frequency identification devices (RFIDs), and their inbound and outbound flights were monitored as well as their homing and hive behavior, including their rest during the day and sleep at night. RFID-marked bees behaved no differently than unmarked bees, both inside and outside the hive.

The team found that after the forced navigation task, the bees slept longer during the first part of the night, but their other foraging behavior remained unchanged. To test whether this increase in sleep might reflect some sort of learning or memory process, the researchers decided to disturb the slumber of select bees by placing them in a box that was gently agitated for 8 hours during the night.

The next day, both sleep-deprived and rested bees underwent another forced navigation task, in which they were released 600 m from the hive in a novel location. Both groups performed equally well on this task, indicating that lack of sleep did not affect the bees' navigational learning process. But after a second night of disturbed sleep followed by the same forced navigation task, sleepy honey bees were just as likely to get lost as they had been the day before, whereas their well-rested counterparts performed dramatically better, cutting their odds of getting lost by half. Interestingly, the time it took to successfully return home did not vary between groups for the first and second homing flights. This result implies that sleep deprivation did not disrupt the bees' ability to access the memory used during the first homing flight but rather interfered with the consolidation of the newly acquired navigational memory.

In short, sleepy honey bees have a harder time remembering lessons learned the day before than their well-rested hivemates.