Is that a question? Maybe you're confused by the plural ending of får. It is ett får, fåret in singular and the plural is får (indeterminate) and fåren (determinate).
I think what he wanted to ask was why it's "are" and not "is" in the translation. Anyway, "sheep" is a strange case just like "fish". It can be both singular or plural.
I belive flyttas implies a form of to be. In english are can be a form of to be.
Yes, flyttas is the passive – as in 'to be moved'.
The active form is flytta = move.