The second one faldage, I always assume that if it is plural then "are" is the right use, but "is" would be correct for singular, but if it is the collective being used (herd of lions) I would say
the herd is moving this way
not
the herd are moving this way
But
The herds are moving this way
Would be the correct form as it is plural herds
I might be wrong though... grin

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