There's almost nothing as cliché as a rooster crowing at dawn, and researchers say the birds actually know what time of day it is, and it has nothing to do with the light. The research was published in the journal Current Biology. For their research, Japanese scientists from Nagoya University kept a group of birds bathed in light constantly, and found that those who were kept under dim lighting constantly were still crowing eating morning just before dawn. Scientists say the "cock-a-doodle-doo" behavior is linked to their cardiac rhythm. (UPI)
