Why do roosters crow? other than to wake ya the %#)! up?

Question

Why do roosters crow? other than to wake ya the %#)! up?

Answer 1

Mine crows after it's chased my dog around, or after it thinks it protected the females from danger.  

Answer 2

they do not do it to wake you up.

They crow do to the high levels of testosterone in their bodies.

and they don't just crow in the mornings which is a common theory people think.

roosters crow at all times of the day

particularly when another rooster is around and they crow at each other to proclaim dominance and defend their flock of hens and their "territory"

also if a rooster is disturbed during the night (example. .  by a car door being slammed) then it will crow then to alert his hens and to try and get it to stop.