No one has seen a flock of birds like this in years, he thought.
They look like a flock of birds taking off from the bottom.
The great hall was filled with a flock of birds.
A flock of birds might drive a powerful animal away from food.
Finally you spot something coming south, but it's a flock of birds.
A flock of small black birds came across the building in a desperate way.
It would be like a flock of birds in flight.
They are usually found in small flocks of less than ten birds.
What looked like a flock of birds rose from deep in the city and headed our way.
High in the air there were flocks of dark birds.
