Hives are busy places. Young bees scurry around 24/7 doing the chores, while older bees spend the day foraging and sleep at night. `Their around-the-clock pattern of activity raises the question of whether young bees sleep as foragers do,' say Ada Eban-Rothschild and Guy Bloch. Working at the Hebrew University of Jerusalem, the pair filmed and monitored old and young bees' activities to see whether young bees sleep (p. 2408).
According to the team, they do and their sleep patterns were quite similar. The 3 day olds slept as deeply as elderly foragers, moving down through light and medium sleep until they reach deep sleep. But the way the youngsters moved between different sleep states was different from their elders. Instead of waking up immediately, like the foragers who move directly from deep sleep to consciousness, the youngsters sometimes dipped back down into deep sleep when it had looked as if they might be about to wake, and often moved back and forth between light, medium and deep sleep. Also, the youngsters were all over the place, compared with the foragers, during the day. Once foragers wake in the morning they remain active until sunset, but the youngsters only woke for several hours at a time before dozing off again.
Overall the youngsters slept as much as their elders and were as easy to wake when the lights went on, but the older bees had a well-defined sleep pattern that the youngsters lacked. So young bees do sleep, despite their 24 h lifestyle.
- © The Company of Biologists Limited 2008