These bumblebees were tagged with radio chips so scientists could follow their foraging patterns during the Arctic summer. ((Ralph Stelzer/BMC Biology) )

While some creatures take advantage of the Arctic's midnight sun to be more productive, it turns out bees work strictly to rule, according to scientists who say the discovery is unexpected.

Writing in the current issue of the peer-reviewed journal BMC Biology, Ralph Stelzer and Lars Chittka from Queen Mary University in London said they expected bees to venture out around the clock to bring back food to the colony.

In bee colonies further south where there is still a distinct day and night during the summer months, workers leave the nest at dawn and stay out looking for food till sunset, making the most of daylight hours.

So the researchers thought Arctic bees would use the 24 hours of available summer daylight to gather food and thus increase the size of their colony. But when the researchers tested their theory in Northern Finland over the summer of 2007, they realized they had it all wrong. 

"We found that bees do not naturally take advantage of this opportunity, suggesting that there is some benefit to an 'overnight' break," Stelzer said in a release.

The researchers studied both native bees and a group of bee colonies they imported into the Arctic. They glued radio tags to slightly more than 1,000 worker bees and tracked their movements over the course of several weeks.

It turns out the bees like to turn in before midnight. The radio tags showed the bees foraged mostly between 8 a.m. and 11 p.m., with activity peaking around midday.

The researchers suggest the trigger for rest could be the dip in temperatures during the "night" even though the sun is still shining. "Also, it has been suggested that a period of sleep helps bees to remember information gained during the day's foraging," they write.