First, let's look at this anticipatory predawn crowing that occurs roughly two hours before dawn.
It also looks like the roosters are more likely to begin crowing in the morning hours if they are suddenly exposed to light.
The crowing of roosters has intrigued people across cultures, exemplified in the way we have terms to refer to it.
The mysteries around circadian rhythms can help us deal with insomnia, and with the problems that people grapple with when they work on night shifts, as so many Filipinos do now in call centers-yes, the guys who leave work at dawn, bleary-eyed, amid roosters crowing.