Can bees turn off their internal clocks? Carrie Straight 06.01.01 Many animals’ bodies maintain a type of internal clock that roughly follows a 24-hour period. The behavior of these animals follows this circadian rhythm (24-hour cycle). For animals like humans Homo sapiens it is not good to force the body to change these natural rhythms. For example, it is not good for our health to disrupt our sleep. Honeybees, Apis spp., are another animal that has a circadian rhythm, but only in older bees. Young bees, called nurses, tend to the larvae all day, without obvious changes in rhythms throughout the day. When these bees are about 3 weeks old, they have a new task that requires a circadian clock. This task is to go out and collect pollen. (Now these bees are called foragers instead of nurses). The bees now have to know when the flowers will be open and they must be able to use the sun to tell directions. The unique thing about bees is that they can change back to having no circadian rhythm without apparent problems.     A couple of scientists from Illinois wanted to investigate if they could force the bees to change their behavioral rhythms. Older foraging bees can change back to being a “nurse bee” and take care of the larvae as it did when it was younger. The bees will change behavior naturally, when there is a shortage of “nurses”, but do they also change their circadian rhythms? Can bees turn off their circadian clocks? To test these questions, the researchers did an experiment in which they created three colonies of bees. They created each colony from about 2000 foragers, a queen, and some young (there were no nurses). In these new colonies, some foragers changed back to becoming full-time nurses. Some foragers became part-time nurses and other foragers did not nurse at all. The new full-time nurses got rid of their circadian rhythms and changed back to their all day nursing activities. Because these foragers-turned-nurses successfully raised the queen’s young, there seems to be no immediate difficulty in turning off their circadian clocks. Too bad humans can’t do that, when it comes time to cram for a test! CLICK HERE for more information! Bloch, Guy and Gene E. Robinson. 2001. Reversal of honeybee behavioural rhythms. Nature 410: 1048. ©2001 The Aurora Collection, Inc. All Rights Reserved. Site Development by: Interactive Multimedia. Inc.