When is "a flock of" used?
Native speaker’s answer
Rebecca
You can use "a flock of" when referring to a large gathering of people or a group of birds, sheep, or goats. Here it's used to refer to a group of birds! Ex: There's a flock of ducks at the dam. Ex: We went to the zoo, and there was a flock of children at the horse pen. Ex: Look over there! It's a flock of sheep.