Researchers at The University of Queensland have discovered
that, like humans, flies sleep in stages of different intensities.
The UQ Queensland Brain Institute's Associate Professor
Bruno van Swinderen said that human sleep involved the rapid eye movement (REM)
stage, or light sleep during which dreaming typically occurred, and several
stages of non-REM sleep, or deep sleep.
“We have shown that sleep in flies also appears to alternate
between lighter and deeper sleep stages, suggesting different functions for
each even in the smallest animal brains.”