Yes, MIGRATORS is a Scrabble word!

Letter values in Scrabble US: M 3, I 1, G 2, R 1, A 1, T 1, O 1, R 1, S 1.

Is it a valid word?

MIGRATORS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

traveler who moves from one region or country to another
an animal (especially birds and fish) that travels between different habitats at particular times of the year