Without those eight or so hours of precious shut-eye, many of us feel dazed, sluggish and downright useless. Sleep might be thought of as the great equalizer — birds do it, bees do it, every animal with a brain does it. But a new study suggests that might not be quite right after all.

A study published today in the journal Science Advances found that some members of a species of fruit fly could, to the jealousy of humans, function on practically no sleep. After being kept awake for severa