Santa’s Reindeer

"Now Dasher! Now Dancer! Now, Prancer and Vixen! On, Comet! On, Cupid! On, Donner and Blitzen! To the top of the porch! To the top of the wall! Now dash away! Dash away! Dash away all!"

With less than a month until Christmas Eve, Santa thinks that his reindeer team is running a little slowly. He wants to adjust the line-up to see if he can make his deliveries and return to the North Pole, Mrs. Claus, and a warm fire a little more quickly this year.

Santa needs eight reindeer to pull his sleigh full of toys. There is only one way that the harnesses can be connected to the sleigh: the reindeer must be arranged in four rows, with two reindeer in each row. How many different ways can the reindeer be arranged to pull the sleigh?