What is a rooster sound called?

crowing
The rooster says “COCK-A-DOODLE-DOO”

When the rooster does this, we say it is crowing. The male is called a rooster or cock. The female is called a hen, and the sound it makes is called clucking.

What does a rooster yell?

The most common reason is the wake up crow. This is simply their way of saying good morning and leading the flocks out to forage. However roosters can also crow to warn their flock or to announce a territorial boundary.