Lots of birds are flying in/over the sky

[Winwin2011]

Lots of birds are flying in/over the sky.

Are both in/over correct in the above sentence?

Thanks.

 

[MikeNewYork]

Lots of birds are flying in/over the sky.

Are both in/over correct in the above sentence?

Thanks.

No. Birds cannot fly over the sky.

 

[emsr2d2]

Depending on your definition of the sky, nothing can fly over the sky.