When birds migrate and take to the sky, they are both in harmony with nature and each other. These sometimes giant flocks, move together as one, often in different formations like a giant cloud.
The phenomenon is known as Murmuration. Director Neels Castillon actually filmed one, almost by accident adding that
We were shooting for a commercial, waiting for an helicopter flying into the sunset, when thousands and thousands of birds came and made this incredible dance in the sky. It was amazing, we just forgot our job and started this little piece of poetry.